The size of a television is the length of the diagonal of its screen in inches. The aspect ratio of the screens of older televisions is 4:3, while the aspect ratio of newer wide-screen televisions is 16:9. Find area of an older 35-inch television whose screen has an aspect ratio of 4:3
Answers
Greetings from Brasil...
The TV format is 4:3.
4 ÷ 3 = 1.33...
Let's assign the smallest side of the TV screen as X. Since the ratio between the sides is 4:3 = 1.33, then the other side (the largest) will be 1.33 times larger than the smaller side X, that is
smaller side = X
bigger side = 1.33X
The diagonal expression of the rectangle is:
D = √(base² + height²)
35" = √[(1.33X)² + X²]
35" = √(1.7689X² + X²) squaring both members
(35")² = 1.7689X² + X²
1225" = 2.7689X²
X² = 1225/2.7689
X² = 442.414
X = √442.414
X ≅ 21"
Tthe bigger side:
1.33X
1.33 · 21 ≅ 28"
Rectangle Area = base × height
Rectangle Area = 28 × 21
Rectangle Area = 588
Related Questions
The sequence below represents Marisa’s fine at the library for each day that she has an overdue book: $0.50, $0.65, $0.80, $0.95, $1.10, ... Which equation represents Marisa’s library fine as a function of a book that is n days overdue? f(n) = 0.15n f(n) = 0.50n f(n) = 0.15n + 0.35 f(n) = 0.50n + 0.15
Answers
Answer:
f(n) = 0.15n + 0.35Step-by-step explanation:
The sequence of the problem above is an arithmetic sequence
For an nth term in an arithmetic sequence
F(n) = a + ( n - 1)d
where a is the first term
n is the number of terms
d is the common difference
To find the equation first find the common difference
0.65 - 0.5 = 0.15 or 0.80 - 0.65 = 0.15
The first term is 0.5
Substitute the values into the above formula
That's
f(n) = 0.5 + (n - 1)0.15
f(n) = 0.5 + 0.15n - 0.15
The final answer is
f(n) = 0.15n + 0.35Hope this helps you
Answer:
The correct option is: f(n) = 0.15n + 0.35Step-by-step explanation:
Took the math test on edge
In the figure below.. Please help!!!
Answers
====================================================
Explanation:
Both AB and XY are the first two letters of ABC and XYZ respectively. So we have one fraction of AB/XY = 2/7.
AC and XZ are the first and last letters of ABC and XYZ respectively. We can form another fraction AC/XZ. I'm dividing in the same order of small over large to keep things consistent. As you can probably guess, the order of the letters ABC and XYZ are important so we see how the angles match up and how the proportional sides match up.
Because the triangles are similar, the two fractions formed earlier are equal to one another.
The equation we need to solve is AB/XY = AC/XZ
-----
AB/XY = AC/XZ
2/7 = 3/N ... plug in given values
2N = 7*3 .... cross multiply
2N = 21
N = 21/2 .... divide both sides by 2
N = 10.5
ZX is 10.5 units long.
HELP NEED PRECALC HELP WILL GIVE BRAINLIEST PLEASE HELP
Answers
From your earlier questions, we found
[tex]2\sin(4\pi t)+5\cos(4\pi t)=\sqrt{29}\sin\left(4\pi t+\tan^{-1}\left(\dfrac52\right)\right)[/tex]
so the wave has amplitude √29. The weight's maximum negative position from equilibrium is then -√29, so you are solving for t in the given interval for which
[tex]\sqrt{29}\sin\left(4\pi t+\tan^{-1}\left(\dfrac52\right)\right)=-\dfrac{\sqrt{29}}2[/tex]
Divide both sides by √29:
[tex]\sin\left(4\pi t+\tan^{-1}\left(\dfrac52\right)\right)=-\dfrac12[/tex]
Take the inverse sine of both sides, noting that we get two possible solution sets because we have
[tex]\sin\left(\dfrac{7\pi}6\right)=\sin\left(\dfrac{11\pi}6\right)=-\dfrac12[/tex]
and the sine wave has period 2π, so [tex]\sin x=\sin(x+2\pi)=\sin(x+4\pi)=\cdots[/tex].
[tex]\implies 4\pi t+\tan^{-1}\left(\dfrac52\right)=\dfrac{7\pi}6+2n\pi[/tex]
OR
[tex]\implies 4\pi t+\tan^{-1}\left(\dfrac52\right)=\dfrac{11\pi}6+2n\pi[/tex]
where n is any integer.
Now solve for t :
[tex]t=\dfrac{\frac{7\pi}6+2n\pi-\tan^{-1}\left(\frac52\right)}{4\pi}[/tex]
OR
[tex]t=\dfrac{\frac{11\pi}6+2n\pi-\tan^{-1}\left(\frac52\right)}{4\pi}[/tex]
We get solutions between 0 and 0.5 when n = 0 of t ≈ 0.196946 and t ≈ 0.363613.
simplify each expression 17x + 4 - 3x
Answers
Answer:
14x+4
Step-by-step explanation:
17x-3x=14x
A recent national survey found that high school students watched an average (mean) of 7.1 movies per month with a population standard deviation of 1.0. The distribution of number of movies watched per month follows the normal distribution. A random sample of 33 college students revealed that the mean number of movies watched last month was 6.2. At the 0.05 significance level, can we conclude that college students watch fewer movies a month than high school students? State the null hypothesis and the alternate hypothesis.
Answers
Answer:
H0: μc ≤ μs Ha :μc > μs
Step-by-step explanation:
The null and alternate hypotheses can be stated as
H0: μc ≤ μs Ha :μc > μs one tailed test
Where
μc = Mean of college students watching movies in a month
μs = Mean of school students watching movies in a month
For one tailed test of α =0.05 the value of Z= ± 1.645
The critical region will be Z > ± 1.645
It is of importance to note that by rejecting the null hypothesis and accepting the alternate hypothesis we are automatically rejecting all values of mean that are greater than 7.1
In a frequency distribution of 290 scores, the mean is 99 and the median is 86. One would expect this distribution to be:
Answers
Answer:
positively skewed to the right
Step-by-step explanation:
The measure of the central tendency is a profound way to describe the mean, median and mode. The measure of central tendency indicates where the center of distribution tends to be. The measure of central tendency provide a validity and answers whether the scores are high or generally low.
In this measure,The mean is usually pulled to the tail. The skewed is determined by where the tail goes, to the right side , it is positively skewed and to the left side , it is known as negatively skewed distribution.
Given that:
In a frequency of distribution of 290 scores,
the mean = 99
the median = 86
One would expect this distribution to be; positively skewed to the right since the mean value is greater than the median value.
What is the value of x to the nearest tenth?
Answers
Answer:
x=9.6
Step-by-step explanation:
The dot in the middle represents the center of the circle, so therefore, the line that is represented by 16 is the radius. Since that is the radius, the side that is the hypotenuse of the small triangle is also 16, since they have the same distance.
The line represented by 25.6 with x as its bisector shows that when we divide it by 2, the other side of the triangle besides the hypotenuse is 12.8.
Now that we have the two sides of the triangle, we can find the last side (represented by x). Use pythagorean theorem:
[tex]a^2 +b^2=c^2\\x^2+(12.8)^2=16^2\\x^2+163.84=256\\x^2=92.16\\x=9.6[/tex]
what percent of sales were shoes or socks? A.9% B. 39% C.52% D. 61%
Answers
Answer:
it is 9%
Step-by-step explanation: the socks persent is the correct answer
Answer: D. 61%
Step-by-step explanation:
Assume a significance level of alpha = 0.05 and use the given information to complete parts (a) and (b) below. Original claim: The standard deviation of pulse rates of a certain group of adult males is more than 11 bpm. The hypothesis test results in aP-value of 0.2761.a. State a conclusion about the null hypothesis.(Reject H0 or fail to reject H0.) Choose the correct answer below.A. Fail to reject H0 because the P-value is less than or equal to alphaα.B. Reject H0 because the P-value is less than or equal to alphaα.C.Fail to reject H0 because the P-value is greater than alphaα.D. Reject H0 because the P-value is greater than alphaα.b. Without using technical terms, state a final conclusion that addresses the original claim. Which of the following is the correct conclusion?A. The standard deviation of pulse rates of the group of adult males is more than 11 bpm.B. There is not sufficient evidence to support the claim that the standard deviation of pulse rates of the group of adult males is more than 11 bpm.C. The standard deviation of pulse rates of the group of adult males is less than or equal to 11 bpm.D. There is sufficient evidence to support the claim that the standard deviation of pulse rates of the group of adult males is more than 11 bpm.
Answers
Answer:
a
The correct option is B
b
The correct option is D
Step-by-step explanation:
From the question we are told that
The level of significance is [tex]\alpha = 0.05[/tex]
The p-value is [tex]p = 0.2761[/tex]
Considering question b
Given that the [tex]p< \alpha[/tex] then the null hypothesis is rejected
Considering question b
Given that the original claim is The standard deviation of pulse rates of a certain group of adult males is more than 11 bpm
Then the null hypothesis is [tex]H_o : \sigma = 11[/tex]
The reason why the null hypothesis is write like this above is because a null hypothesis expression can not contain only a > or a < but only allows = [tex]\le , \ and \ \ge[/tex]
and the alternative hypothesis is [tex]H_a : \sigma > 11[/tex]
Now given that the null hypothesis is rejected, it mean that there is sufficient evidence to support original claim
Order the following from least to greatest.
1/16
.0173
1/7
2.2
-0.25
Answers
Answer:
1.-0.25 2..0173 3. .1/16 4. 1/7 5.2.2
Step-by-step explanation:
You want to put all numbers in fractions to see which numbers are smallest
6th grade math. :) help me please
Answers
Answer:
8 3/4
Step-by-step explanation:
The decimal 3.5 as an improper fraction is 35/10.
Answer:
[tex]8\frac{3}{4}[/tex]
Step-by-step explanation:
To write as a mixed number means that you will have a whole number and a fraction together. To find the mixed fraction version, see how many times the denominator (bottom) fits into the numerator (top) evenly.
4, 8, 12, 16, 20, 24, 28, 32, 36
1 2 3 4 5 6 7 8 9
4 can go into 35 '8' times without being greater than the numerator. 8 is the whole number. Now subtract the original numerator by the product of 4 and 8, which is 32:
[tex]35-32=3[/tex]
3 is the new numerator. Keep the same denominator. Insert all values:
[tex]\frac{35}{4}=8\frac{3}{4}[/tex]
:Done
i need help really bad
Answers
Answer:
see explanation
Step-by-step explanation:
If f(x) and [tex]f^{-1}[/tex] are inverse functions, then
f([tex]f^{-1}[/tex])(x) = x
Thus substitute x = [tex]f^{-1}[/tex] (x) into f(x)
f([tex]\frac{x+6}{5}[/tex] )
= 5 ([tex]\frac{x+6}{5}[/tex] ) - 6
= x + 6 - 6
= x
Thus f(x) and [tex]f^{-1}[/tex] (x) are inverse functions
In the number 5,794,032,861, which digit is in the ten millions place?
09
0 5
o 7
0 4
Answers
what is the equation for a parabola with a focus at (2,2) and a directix of x=8
Answers
Answer:
( y-5) ^2 =-12(x-2)
Step-by-step explanation:
focus at (2,2) and a directrix of x=8
Using the equation
( y-k) ^2 = 4p(x-k)
where ( h,k) is the vertex
The vertex is 1/2 way between the focus and the directrix
( 2+8)/2 , 2
5,2 is the vertex
( y-5) ^2 = 4p(x-2)
distance from the focus to the vertex and from the vertex to the directrix is
| p|
2-5 = p
-3 = p
( y-5) ^2 = 4*-3(x-2)
( y-5) ^2 =-12(x-2)
What is the error in this problem
Answers
Answer:
12). LM = 37.1 units
13). c = 4.6 mi
Step-by-step explanation:
12). LM² = 23² + 20² - 2(23)(20)cos(119)°
LM² = 529 + 400 - 920cos(119)°
LM² = 929 - 920cos(119)°
LM = [tex]\sqrt{929+446.03}[/tex]
= [tex]\sqrt{1375.03}[/tex]
= 37.08
≈ 37.1 units
13). c² = 5.4² + 3.6² - 2(5.4)(3.6)cos(58)°
c² = 29.16 + 12.96 - 38.88cos(58)°
c² = 42.12 - 38.88cos(58)°
c = [tex]\sqrt{42.12-20.603}[/tex]
c = [tex]\sqrt{21.517}[/tex]
c = 4.6386
c ≈ 4.6 mi
PLZZZZ helpppp will give good rating say thanks and say thank you on your account
Yak Travel Agency arranges trips for climbing Mount Everest. For each trip, they charge an initial fee in addition to $0.15 for each vertical meter climbed. For instance, the price for climbing all the way to the summit, which is 3500 meters above the base of the mountain, is $645. Let F represent the fee (in dollars) of a trip where they climbed ddd vertical meters. Complete the equation for the relationship between the fee and vertical distance.
Answers
X=120
F= 0.15d + 120
Solve for y:1(y+3)=2(y+−4)+−7
Answers
Answer:
[tex]\large \boxed{{y=18}}[/tex]
Step-by-step explanation:
[tex]1(y+3)=2(y+-4)+- 7[/tex]
Expand brackets.
[tex]y+3=2y-8+- 7[/tex]
Simplify.
[tex]y+3=2y-15[/tex]
Add -y and 15 on both sides.
[tex]y+3-y+15=2y-15-y+15[/tex]
Simplify.
[tex]3+15=2y-y[/tex]
[tex]18=y[/tex]
Answer:
18
Step-by-step explanation:
● 1 (y+3) = 2 (y+(-4) )+ (-7)
When you multiply by 1 you get the same result.
● y+3 = 2 (y+(-4))+(-7)
When you have a + sign with a - sign write -.
● y+3 = 2(y-4)-7
Multiply 2 by (y-4) and simplify
● y+3 = (2y-8)-7
● y+3 = 2y -8-7
● y+3 = 2y -15
Add 15 to both sides
● y +3+15 = 2y-15 +15
● y + 18 = 2y
Sibstract y from both sides
● y +18 - y = 2y -y
● 18 = y
Open the graphing tool. Move the slider for the equation y = kx3 to a position of your choice, where k ≠ 1. Next, move the slider of y = (kx)3 so the two graphs lie on top of one another. How do the values of k compare with one another in this situation? Why do you think that is?
Answers
Answer:
For the functions to coincide, the value of k in y = (kx)3 must be smaller than in y = kx3. This is because the value of y changes more rapidly when k is cubed inside the parentheses. The behavior of the functions is similar since a vertical stretch is similar to a horizontal compression.
Step-by-step explanation:
PLATO
Determine which is the appropriate approach for conducting a hypothesis test. Claim: The mean RDA of sodium is 2400mg. Sample data: n150, 3400, s550. The sample data appear to come from a normally distributed population.
Answers
Answer:
Use the student t distribution
Step-by-step explanation:
Here is the formula
t = (x - u) ÷(s/√N)
From the information we have in the question:
n = 150
s = 550
x = 3400
u = mean = 2400
= 3400 - 2400÷ 500/√150
= 1000/44.9
= 22.27
At 0.05 significance level, df = 149 so t tabulated will be 1.65.
We cannot use normal distribution since we do not have population standard deviationWe cannot use normal distribution since we do not have population standard deviationChisquare cannot be used since we are not testing for population varianceWe cannot use normal distribution since we do not have population standard deviationChisquare cannot be used since we are not testing for population varianceThe parametric or bootstrap method cannot be used either.A random sample of 35 undergraduate students who completed two years of college were asked to take a basic mathematics test. The mean and standard deviation of their scores were 75.1 and 12.8, respectively. In a random sample of 50 students who only completed high school, the mean and standard deviation of the test scores were 72.1 and 14.6, respectively In order to test the equal variance assumption for two populations, Can we assume population variances are equal at the 10% significance level? (sigma subscript 1 superscript 2 space equals space sigma subscript 2 superscript 2 )
Answers
Answer:
The 90 % confidence limits are (-2.09, 8.09).
Since the calculated values do not lie in the critical region we accept our null hypothesis.
Step-by-step explanation:
The null and alternative hypothesis are given by
H0: σ₁²= σ₂² against Ha: σ₁² ≠ σ₂²
Confidence interval for the population mean difference is given by
(x`1- x`2) ± t √S²(1/n1 + 1/n2)
Where S ²= (n1-1)S₁² + S²₂(n2-1)/n1+n2-2
Critical value of t with n1+n2-2= 50+ 35-2= 83 will be -1.633
Now calculating
S ²=34* (12.8)²+ (14.6)²*49/83= 192.96
Now putting the values in the t- test
(75.1 -72.1) ± 1.633 √ 192.96(1/35 +1/50)
=3 ± 5.09
=-2.09, 8.09 is the 90 % confidence interval for the difference
The 90 % confidence limits are (-2.09, 8.09).
Since the calculated values do not lie in the critical region we accept our null hypothesis.
If 5x + 2 =12x- 5, then x = ?
Answers
Answer:
x = 1
Step-by-step explanation:
First, move all the variables to one side by subtracting 5x on both sides:
5x + 2 = 12x - 5
2 = 7x - 5
Add 5 to both sides:
7 = 7x
1 = x
Answer:
x=1
Step-by-step explanation:
5x + 2 =12x- 5
Subtract 5x from each side
5x-5x + 2 =12x-5x- 5
2 = 7x-5
Add 5 to each side
2+5 = 7x-5+5
7 = 7x
Divide each side by 7
7/7 = 7x/7
1 =x
Solve for x in the equation below. Round your answer to the nearest hundredth. Do not round any intermediate computations. 12-8x=5
Answers
x=7/8 ≈ 0.88
0.88
Answer:
x = 0.88Step-by-step explanation:
[tex]12-8x=5\\\\Collect\:like\:terms\\\\-8x =5-12\\\\-8x = -7\\\\Divide\:both\:sides\:by -8\\\frac{-8x}{-8} \\=\frac{-7}{-8} \\\\x = 0.875\\\\x = 0.88[/tex]
If you have $100 in a savings account earning 3% interest per year, how much will you have in
two years?
Answers
Answer:
$106
Step-by-step explanation:
You have 100$ in savings account
Interest rate =3%
Time = 2 years
Total in 2 years:
100 + 2*3% = 100 *1.06= $106The interest formula is as follows:
Amount Invested · Rate = Interest Earned
If we invest $100 at 3% interest per year,
how much do we earn that year?
Well based on our formula, we can simply multiply 100 · 3%.
Think of the 3% as 3/100.
So we have 100 · 3/100 and the 100's cancel and we're left with 3.
So $3 is earned in 1 year.
So after two years, you will have double that or $6.
Help me please please please please
Answers
Answer:
1.
d. (-14) + (-8)
2.
a. (-14) + 8
Step-by-step explanation:
(-14) - 8 is equal to (-14) + (-8) because we still add two negative values so the result wouldn't change.
(-14) - (-8) is equal to (-14) + 8 because there's two negative sign in front of 8 and two negative values multiplied makes a positive result.
Answer:
1. D
2. A
Step-by-step explanation:
1. It asks you what expression has the same value as (-14)-8. All you need to do is find other equations that have the same value as that. So the equation is -14-8. IF a negative is outside a parenthesis with a positive number inside like -(+5), it is going to be -5. If it's both negative: -(-5), it will be +5. If it is both positive: +(+5), it is going to be +5.
IMPORTANT!
- and + = -
- and - = +
+ and + = +
What we are looking for: -14-8
So choice A is (-14)+8 which is simplified to -14+8. So, this one isn't right.
Choice B: 14-(-8)= 14+8. So, it's incorrect.
Choice C: 14+(-8)= 14-8. Again, it's not -14-8 so it's not right.
Choice D: (-14)+(-8)= -14-8. This equation matches the one we are looking for! So it's correct!
2. Same thing as number 1. Let's simplify the equation it wants us to find first.
(-14)-(-8)= -14+8
So -14+8 is what we are looking for.
Choice A: (-14)+8= -14+8. It matches! So it is correct. Let's look at the other options anyway.
Choice B: 14-(-8)= 14+8. Nope. Not right.
Choice C: 14+(-8)= 14-8 because - always beats +. So, this one is also incorrect.
Choice D: (-14)+(-8)= -14-8. Oops, this is also wrong. So choice A is the right answer.
Keep in mind, when you start getting questions like this with numbers inside the parenthesis as well, you want to remember the same rules for positive and negative, but also multiply the numbers together:
(When there is a number outside and inside a parentheses, multiply them.)
2(5)=10, CORRECT! 2+(5) is not 2 times 5. It's whatever is closest to the parentheses, in this case being the positive sign. So + and 5 is just 5!
IMPORTANT!
-2(-5)= - and - is positive, so positive (2 times 5). Positive 10.
-2(+5)= - and + is negative, so negative (2 times 5). Negative 10.
+2(+5)= + and + is positive, so positive (2 times 5). Positive 10.
Factor.
x2 – 5x - 36
(x - 9)(x + 4)
(x - 12)(x + 3)
(x + 9)(x - 4)
(x + 12)(x - 3)
Answers
Answer:
The answer is option AStep-by-step explanation:
x² - 5x - 36
To factor the expression rewrite -5x as a difference
That's
x² + 4x - 9x - 36
Factor out x from the expression
x( x + 4) - 9x - 36
Factor out -9 from the expression
x( x + 4) - 9( x+ 4)
Factor out x + 4 from the expression
The final answer is
( x - 9)( x + 4)Hope this helps you
Answer:
[tex] \boxed{(x - 9) \: (x + 4) }[/tex]
Option A is the correct option.-
Step-by-step explanation:
( See the attached picture )
Hope I helped!
Best regards!
An oblique cone has a radius of 5 units and a height of 9 units. What is the approximate volume of the oblique cone? Use π ≈ 3.14 and round to the nearest tenth. 117.8 cubic units 141.3 cubic units 235.5 cubic units 282.6 cubic units
Answers
Answer:
235.6 units^3
Step-by-step explanation:
The formula for the volume of the oblique cone is the same as for the volume of a right circular cone: V = (1/3)(base area)(height).
Here that comes to V = (1/3)(π)(5 units)^2*(9 units), or
V = 75π units^3, or approximately 235.6 units^3
Answer:
235.5 cubic units
Step-by-step explanation:
A set of 9 numbers {3, 3, 4, 5, 5, 5, 6, 7, 7} has a mean of 5. Another number is added to the set, and the mean becomes 6. What number is added to the set?
Answers
Answer:
15
Step-by-step explanation:
3 + 3+ 4+ 5+ 5+ 5+ 6+ 7+ 7=45
You would then divide that my 9(the amount of numbers) to get three
(3 + 3+ 4+ 5+ 5+ 5+ 6+ 7+ 7)/9
=3
If you are adding a number the numbers would be
3 + 3+ 4+ 5+ 5+ 5+ 6+ 7+ 7+?/10
Its ten because now you would have 10 numbers.
You know it equals 6, so you ask yourself: What divided by 10 would give you 6 or this equation:
( 3 + 3+ 4+ 5+ 5+ 5+ 6+ 7+ 7+?)/10=6
(45+?)/10=6
multiply both sides of the equal sign by 10
10(45+?)/10=6*10
The 10 on the bottom of the left side cancels out.
(45+?)=60
Subtract 15 from both sides of the equal sign
45+?-45=60-45
?=15
Which of the following is an example of closure? (1 point)
The equation 5 - 5 = 0 is an example of the natural numbers being closed under subtraction
The equation 1.5 +1.6 = 3.1 is an example of the rational numbers being closed under addition
The equation 4 - 6 = -2 is an example of the whole numbers being closed under subtraction
The equation 1+0= 1 is an example of the natural numbers being closed under addition
Answers
Answer:
The equation 1+0=1
Step-by-step explanation:
Other options are not eligible because
1 option -Natural numbers cannot be closed under subtraction
2 option-The equation is not having proper rational numbers, they are decimals
3 option-Whole numbers cannot be closed under subtraction
Thank you!
Please help me I will mark brainliest! The ratio of the number of boys to the number of girls in a school is 3:4. One-third of the boys and three-eighths of the girls wear spectacles, If there are 612 pupils who do not wear spectacles, a)find the total number of the pupils in the school, and b) how many more girls than boys are there in the school
Answers
Answer:
a) 952
b) 136
Step-by-step explanation:
Ratio of b:g = 3:4, based on this we have:
Number of boys = 3xNumber of girls = 4xTotal number of pupils = 3x+4x = 7xNumber of spectacle wearers:
1/3*3x + 3/8*4x = x + 3/2x = 2.5xNumber of those not wearing spectacles:
7x - 2.5x= 4.5xAnd this number equals to 612, then we can find the value of x:
4.5 x = 612x= 612/4.5x= 136a) Total number of pupils:
7x = 7*136 = 952b) The difference in the number of boys and girls:
4x-3x= x = 136Answer:
total number of students: 952
number of girls more than boys :136 more girls
Step-by-step explanation:
1/3 of boys +3/8 girls= spectacles
612 people do not wear spectacles
3:4= boys: girls
total number of students
3+4=7
boys + girls = total ratio
7= total ratio
1/3×3=1 3/8×4=3/2
1+3/2=5/2
7-5/2=9/2 9/2=612 students
If 9/2=612 Then 7=?
7= 7÷ 9/2×612
=952 people
Girls more than boys
if 7= 952
3= 3/7 × 952=408 boys
if 7 = 952
4= 4/7 ×952=544girls
Girls - boys
544- 408 = 136 girls
In a random sample of people, the mean driving distance to work was miles and the standard deviation was miles. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a % confidence interval for the population mean . Interpret the results. Identify the margin of error.
Answers
Complete Question
In a random sample of ten people, the mean driving distance to work was 23.1 miles and the standard deviation was 6.6 miles. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 99% confidence interval for the population mean Interpret the results. Identify the margin of error.
Answer:
The 99% confidence interval is [tex]16.32< \mu <29.88[/tex]
The interpretation is that there is 99% confidence that the true mean lies within the limits
The margin of error is [tex]E = 6.783[/tex]
Step-by-step explanation:
From the question we are told that
The sample mean is [tex]\= x = 23.1[/tex]
The standard deviation is [tex]\sigma = 6.6 \ miles[/tex]
The sample size is n = 10
Generally the degree of freedom is mathematically represented as
[tex]df = n-1[/tex]
=> [tex]df = 10-1[/tex]
=> [tex]df =9[/tex]
Given that the confidence level is 99% , the n the level of significance is mathematically evaluated as
[tex]\alpha = 100 - 99[/tex]
[tex]\alpha =1\%[/tex]
[tex]\alpha =0.01[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] with a df of 9 from from the student t-distribution table the value is
[tex]t _{\frac{\alpha }{2} , df } = 3.250[/tex]
Generally the margin of error is mathematically represented as
[tex]E = t_{\frac{\alpha }{2} , df } * \frac{\sigma }{\sqrt{n} }[/tex]
[tex]E = 3.250 * \frac{6.6 }{\sqrt{10} }[/tex]
[tex]E = 6.783[/tex]
The 99% confidence interval is
[tex]\= x - E < \mu < \= x + E[/tex]
=> [tex]23.1 - 6.78 < \mu <23.1 + 6.78[/tex]
=> [tex]16.32< \mu <29.88[/tex]
The interpretation is that there is 99% confidence that the true mean lies within the limits
