Complete Question
Statistics professors believe the average number of headaches per semester for all students is more than 18. From a random sample of 15 students, the professors find the mean number of headaches is 19 and the standard deviation is 1.7. Assume the population distribution of number of headaches is normal.the correct conclusion at [tex]\alpha =0.001[/tex] is?
Answer:
There is no sufficient evidence to support the professor believe
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 18[/tex]
The sample size is [tex]n = 15[/tex]
The sample mean is [tex]\= x = 19[/tex]
The standard deviation is [tex]\sigma = 1.7[/tex]
The level of significance is [tex]\alpha = 0.001[/tex]
The null hypothesis is [tex]H_o: \mu = 18[/tex]
The alternative hypothesis is [tex]H_a : \mu > 18[/tex]
The critical value of the level of significance from the normal distribution table is
[tex]Z_{\alpha } = 3.290527[/tex]
The test hypothesis is mathematically represented as
[tex]t = \frac{\= x - \mu }{ \frac{\sigma}{ \sqrt{n} } }[/tex]
substituting values
[tex]t = \frac{ 19 - 18}{ \frac{1.7}{ \sqrt{15} } }[/tex]
[tex]t = 2.28[/tex]
Looking at the value of t and [tex]Z_{\alpha }[/tex] we can see that [tex]t < Z_{\alpha }[/tex] so we fail to reject the null hypothesis.
This mean that there is no sufficient evidence to support the professor believe
Let A and B be any two sets. Show that:
Show that (
AUB)', (BUA)' = 0
Step-by-step explanation:
(AUB)' means they are all outside the set A and B so thats 0. Hope it helps
A survey showed that among 785 randomly selected subjects who completed four years of college, 144 of them are smokers and 84 do not smoke (based on data from the American Medical Association). Suppose you want to test at the 0.01 significance level the claim that the rate of smoking among those with four years of college is less than the 27% rate for the general population.
A. State the null and alternative hypotheses.
B. Find the sample statistic and the p-value.
C. What is your conclusion?
Answer:
We conclude that the rate of smoking among those with four years of college is less than the 27% rate for the general population.
Step-by-step explanation:
We are given that a survey showed that among 785 randomly selected subjects who completed four years of college, 144 of them are smokers.
Let p = population proportion of smokers among those with four years of college
So, Null Hypothesis, [tex]H_0[/tex] : p [tex]\geq[/tex] 27% {means that the rate of smoking among those with four years of college is more than or equal to the 27% rate for the general population}
Alternate Hypothesis, [tex]H_A[/tex] : p < 27% {means that the rate of smoking among those with four years of college is less than the 27% rate for the general population}
The test statistics that will be used here is One-sample z-test for proportions;
T.S. = [tex]\frac{\hat p-p}{\sqrt{\frac{p(1-p)}{n} } }[/tex] ~ N(0,1)
where, [tex]\hat p[/tex] = sample proportion of smokers = [tex]\frac{144}{785}[/tex] = 0.18
n = sample of subjects = 785
So, the test statistics = [tex]\frac{0.18-0.27}{\sqrt{\frac{0.27(1-0.27)}{785} } }[/tex]
= -5.68
The value of z-test statistics is -5.68.
Also, the P-value of the test statistics is given by;P-value = P(Z < -5.68) = Less than 0.0001
Now, at a 0.01 level of significance, the z table gives a critical value of -2.3262 for the left-tailed test.
Since the value of our test statistics is less than the critical value of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region.
Therefore, we conclude that the rate of smoking among those with four years of college is less than the 27% rate for the general population.
100 students are interviewed to see which of biology, chemistry or physics they prefer.
59 of the students are girls. 35 of the girls like biology best.
2 of the boys prefer physics.
6 out of the 30 who prefer chemistry are girls.
What percentage of the students prefer biology?
Answer:
50%
Step-by-step explanation:
Girls Boys
total: 59 total: 41
- Chemistry 35 - Physics 2
= 24 = 39
- Chemistry ( 30 - 6 ) 24
= 15
Total boys and girls for Biology = 35 + 15 = 50
% = 50/100*100
= 50%
Hope it helps and also mark it as brainliest!!!!The value (in dollars) of an airplane depends on the flight hours as given by the formula V= 1,800,000 - 250x . After one year, the value of the plane is between $1,200,000 and $1,300,000. Which range for the flight hours does this correspond to?
a. 1800 <= x <= 2100
b. 2200<= x <= 2500
c. 1500<= x <= 1800
d. 2000<= x <= 2400
Answer:
D
Step-by-step explanation:
To determine the range we must solve this inequality;
● 1200000<1800000-250x<1300000
Substract 1800000 from both sides.
● 1200000-1800000<1800000-250x<1300000-1800000
● -600000< -250x < -500000
Divide both sides by 250
● -600000/250 < -250x/250 < -500000/250
● -2400 < -x < -2000
Multiply both sides by -1 and switch the signs
● 2000 < x < 2400
The correct option is D. 2000<= x <= 2400
Given, the value of an airplane depends on the flight hours,
[tex]V= 1800000-250x[/tex], here x is the flight hours.
We have to calculate the range of x After one year.
Since, [tex]V= 1800000-250x[/tex]
[tex]250x=1800000-V\\\\x=\dfrac{1800000-V}{250}[/tex]
Since the value of the plane is between $1,200,000 and $1,300,000. So,
[tex]x=\dfrac{1800000-1200000}{250}[/tex]
[tex]x=\dfrac{600000}{250}[/tex]
[tex]x=2400\\[/tex]
When V is 1300000 then x will be,
[tex]x=\dfrac{1800000-1300000}{250} \\[/tex]
[tex]x=\dfrac{500000}{250}[/tex]
[tex]x=2000[/tex]
Hence the range of x will be from 2000 to 2400.
The correct option is D. 2000<= x <= 2400.
For more details on range follow the link:
https://brainly.com/question/10185991
Which of the following is the solution to the inequality below? -5x — 10 -6 B. x > -2 C. x <-6 D. x < -2
Answer:
x > -6
Step-by-step explanation:
-5x — 10 < 20
Add 10 to each side
-5x — 10+10 < 20+10
-5x < 30
Divide each side by -5, remembering to flip the inequality
-5x/-5 > 30/-5
x > -6
Answer:
x>-6Step-by-step explanation:
[tex]-5x - 10 < 20\\\\\mathrm{Add\:}10\mathrm{\:to\:both\:sides}\\\\-5x-10+10<20+10\\\\\mathrm{Multiply\:both\:sides\:by\:-1\:\left(reverse\:the\:inequality\right)}\\\\\left(-5x\right)\left(-1\right)>30\left(-1\right)\\\\\mathrm{Simplify}\\\\5x>-30\\\\\mathrm{Divide\:both\:sides\:by\:}5\\\\\frac{5x}{5}>\frac{-30}{5}\\\\x>-6[/tex]
(a^8)3/2 in simplest form
Answer:
[tex]\large\boxed{\frac{3}{2}a^{8}}[/tex]
Step-by-step explanation:
([tex]a^{8}[/tex]) * [tex]\frac{3}{2}[/tex]
Remove the parenthesis by multiplying
[tex]\frac{3}{2}[/tex][tex]a^{8}[/tex]
This expression cannot be simplified further
[tex]\large\boxed{\frac{3}{2}a^{8}}[/tex]
Hope this helps :)
The formula for the area of a square is s2, where s is the side length of the square. What is the area of a square with a side length of 6 centimeters? Do not include units in your answer.
Answer:
36
Step-by-step explanation:
formula of area for square:
A=s^2
s=6
A=6^2
A=36
Answer:
36
Step-by-step explanation:
I got it right
a sample from a mummified bull was taken from a certain place. The sample shows that 71% of the carbon-14 still remains. how old is the sample
Answer:
Step-by-step explanation:
Decay of carbon - 14 is exponential in nature . It decays as follows .
[tex]N=N_0e^{-\lambda t}[/tex] λ is called decay constant .
λ = .693 / T where T is half life .
Half life of carbon-14 is 5700 years
λ = .693 / T
= .693 / 5700
= 12.158 x 10⁻⁵ year⁻¹
[tex]N=N_0e^{-\lambda t}[/tex]
N = .71 N₀
[tex].71 N_0 =N_0e^{-\lambda t}[/tex]
[tex].71 =e^{-\lambda t}[/tex]
Taking ln on both sides
ln .71 = - λ t
ln .71 = - 12.158 x 10⁻⁵ t
-0.3425 = - 12.158 x 10⁻⁵ t
t = .3425 / 12.158 x 10⁻⁵
2817 years .
What is the slope of a line perpendicular to y=-7/4x
O A.
IN
O B.
7
O c.
4
-
O D.
7
4
Answer:
y=4/7x
Step-by-step explanation:
perpendicular lines have opposite slopes. that means reciprocal and opposite sign.
Please answer this correctly without making mistakes
Answer: 7 mi
Step-by-step explanation: since the distance from bluepoint to Manchester is 12 9/10 mi and you know that bluepoint to Silverstone is 5 9/10 subtract that and you get 7 mi as your answer
Answer:
7 miles
Step-by-step explanation:
Hey there!
Well given BM and BS, we need to subtract them.
12 9 /10 - 5 9/10
9/10 - 9/10 = 0
12 - 5 = 7
Silvergrove to Manchester is 7 miles.
Hope this helps :)
A random variable is not normally distributed, but it is mound shaped. It has a mean of 14 and a standard deviation of 3. If you take a sample of size 10, can you say what the shape of the sampling distribution for the sample mean is
Answer:
Step-by-step explanation:
from the question,
the mean 14
the standard deviation is 3
and sample size is 10.
since the n which is the sample size is 10, then the distribution is mound shaped.
why?
this is due to the fact that the random variable from which we took the sample is mound shaped.
The sampling distribution of the mean is normally distributed although the question says the random variable is not normally distributed. so the shape is bell shaped and normally distributed.
the standard deviation of the mean is
3/√10
= 0.948
Please answer this correctly without making mistakes
Answer:
so to get a third you divide it by 3
first convert it to fraction
so it is 26/3
so do 26/3 divided by 3
so we do keep switch flip
26/3*1/3
so answer is 26/9 or 2 8/9
Step-by-step explanation:
Answer:
[tex]\large \boxed{\mathrm{2 \ 8/9 \ tablespoons \ of \ red \ chilies }}[/tex]
Step-by-step explanation:
8 2/3 tablespoons of red chilies is required for a recipe.
One-third of the original recipe would mean that the quantity of red chilies will be also one-third.
8 2/3 × 1/3
Convert to an improper fraction.
26/3 × 1/3
Multiply the fractions.
26/(3 × 3) = 26/9
Convert to a mixed fraction.
26/9 = 2 8/9
3
Select the correct answer.
Which equation represents the line that is parallel to y= 2 and passes through (-1,-6)?
OA x=-1
OB
X= 2
OCy= -6
OD. y= 2x - 4
Reset
Next
Hey there! I'm happy to help!
Lines that are parallel have the same slopes because they are increasing or decreasing at the same rate and therefore will never bump into each other.
We see that y=2 has a slope of 0 because there is no x that we can see in the equation. This is just a flat line.
If the line we are looking for is flat; it stays at the same y-value the entire time. We see that the y-value for this line of ours is -6. Therefore, the answer is C. y=-6.
I hope that this helps! Have a wonderful day!
Answer:
Lines that are parallel have the same slopes because they are increasing or decreasing at the same rate and therefore will never bump into each other.
We see that y=2 has a slope of 0 because there is no x that we can see in the equation. This is just a flat line.
If the line we are looking for is flat; it stays at the same y-value the entire time. We see that the y-value for this line of ours is -6. Therefore, the answer is C. y=-6.
Step-by-step explanation:
; ) BELIEVE IN YOURSELF!!!!!!!!!!!!!!!!!
write a thirdthird-degree polynomial expression that has only two terms with a leading term that has a coefficient of five and a constant of negative two
Answer:
5x^3-2
[tex]ax^{3} +bx^{2} +cx+d\\5x^{3}-given\\ d=-2-given\\5x^{3} -2[/tex]
Explanation:
The two terms are [tex]5x^3[/tex] and [tex]2[/tex]. Terms are separated by either a plus or minus.
We can write it as [tex]5x^3+(-2)[/tex] which is an equivalent form. Here the two terms are [tex]5x^3[/tex] and [tex]-2[/tex]. This is because adding a negative is the same as subtracting.
The coefficient is the number to the left of the variable.
The degree is the largest exponent, which helps form the leading term.
The third degree polynomial written above is considered a cubic binomial. "Cubic" refers to the third degree, while "binomial" means there are 2 terms.
We can write something like [tex]5x^3[/tex] as 5x^3 when it comes to computer settings.
Write 11 numbers in a row so that the sum of any 3 consecutive numbers is negative, while the sum of all the numbers is positive. Is it possible?
Explanation:
Let the 11 numbers be {a1, a2, ..., a11} such that a1 is the smallest and a11 is the largest. So, a1 < a2 < ... < a11. Furthermore, these numbers are consecutive.
If we add consecutive numbers to get a negative result, then each of the numbers must be negative. So every value in the set {a1, a2, ..., a11} is a negative value which makes it impossible to have a1+a2+...a11 be a positive sum.
If f(x) = 2x2 – 3x – 1, then f(-1)=
The value of function at x= -1 is f(-1) = 4.
We have the function as
f(x) = 2x² - 3x -1
To find the value of f(-1) when f(x) = 2x² - 3x -1, we substitute x = -1 into the expression:
f(-1) = 2(-1)² - 3(-1) - 1
= 2(1) + 3 - 1
= 2 + 3 - 1
= 4.
Therefore, the value of function at x= -1 is f(-1) = 4.
Learn more about Function here:
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What is the volume of a cube with a side length of
of a unit?
What is the error in this problem
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
How do i do this equation
-3(-2y-4)-5y-2=
Answer:
Step-by-step explanation: distribute -3 to the parenthesis (-2y-4) to eliminate the parenthesis. you’ll be left with 6y +12 -5y-2. From there you combine like terms. do 6y-5y= 1y or just y and 12-2 = 10. your answer would be 10
If f(x)=ax+b/x and f(1)=1 and f(2)=5, what is the value of A and B?
Answer:
[tex]\huge\boxed{a=9 ; b = -8}[/tex]
Step-by-step explanation:
[tex]f(x) = \frac{ax+b}{x}[/tex]
Putting x = 1
=> [tex]f(1) = \frac{a(1)+b}{1}[/tex]
Given that f(1) = 1
=> [tex]1 = a + b[/tex]
=> [tex]a+b = 1[/tex] -------------------(1)
Now,
Putting x = 2
=> [tex]f(2) = \frac{a(2)+b}{2}[/tex]
Given that f(2) = 5
=> [tex]5 = \frac{2a+b}{2}[/tex]
=> [tex]2a+b = 5*2[/tex]
=> [tex]2a+b = 10[/tex] ----------------(2)
Subtracting (2) from (1)
[tex]a+b-(2a+b) = 1-10\\a+b-2a-b = -9\\a-2a = -9\\-a = -9\\a = 9[/tex]
For b , Put a = 9 in equation (1)
[tex]9+b = 1\\Subtracting \ both \ sides \ by \ 9\\b = 1-9\\b = -8[/tex]
How should a musician effectively convey emotions or ideas in a performance?
Answer:
Within the factors hindering expression in music, tempo is the most important number of factors such as your mood.
Step-by-step explanation:
If one wants to convey a message, they should try these:
a) Use real life
b) introduce symbolism
c) convey sensory disruption, e.t.c.
Hope these helps.
Please Help quick!!! What is the value of a missing angle?
Answer:
69
Step-by-step explanation:
90-21=69
Answer:
69 degrees
Step-by-step explanation:
The full angle = 90 degrees.
One part of the full angle = 21 degrees
The other part of the full angle = x
Other angle = 90 - 21
=> the other angle = 69 degrees
Consider the following ordered data. 6 9 9 10 11 11 12 13 14 (a) Find the low, Q1, median, Q3, and high. low Q1 median Q3 high (b) Find the interquartile range.
Answer:
Low Q1 Median Q3 High
6 9 11 12.5 14
The interquartile range = 3.5
Step-by-step explanation:
Given that:
Consider the following ordered data. 6 9 9 10 11 11 12 13 14
From the above dataset, the highest value = 14 and the lowest value = 6
The median is the middle number = 11
For Q1, i.e the median of the lower half
we have the ordered data = 6, 9, 9, 10
here , we have to values as the middle number , n order to determine the median, the mean will be the mean average of the two middle numbers.
i.e
median = [tex]\dfrac{9+9}{2}[/tex]
median = [tex]\dfrac{18}{2}[/tex]
median = 9
Q3, i.e median of the upper half
we have the ordered data = 11 12 13 14
The same use case is applicable here.
Median = [tex]\dfrac{12+13}{2}[/tex]
Median = [tex]\dfrac{25}{2}[/tex]
Median = 12.5
Low Q1 Median Q3 High
6 9 11 12.5 14
The interquartile range = Q3 - Q1
The interquartile range = 12.5 - 9
The interquartile range = 3.5
I need some help with this please :)
Answer:18 ft
Step-by-step explanation: Perimeter=2(L+B)
Perimeter=2(7 + 2)
2×9=18
Answer:
18feet.
Step-by-step explanation:
To find the perimemter of a rectangle, you just add all the sides.
A rectangle has 4 sides in total, where 2 are equal, and the other 2 are als equal.
So, you just add 7+2+7+2, which gives 18.
This is why, the perimeter of this rectangle is 18feet.
Hope this helped, have a nice day!
How do you find x when knowing the probability?
Answer:
x
Step-by-step explanation:
probability is the branch of mathematics concerning numeral descriptions of how likely an event is to occur or how likely it is that a proposition is true
. A discount brokerage selected a random sample of 64 customers and reviewed the value of their accounts. The mean was $32,000 with a population standard deviation of $8,200. What is a 90% confidence interval for the mean account value of the population of customers
Answer:
The 90% confidence interval is [tex]\$ \ 30313.9< \mu < \$ \ 33686.13[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is n = 64
The sample mean is [tex]\= x = \$ 32, 000[/tex]
The standard deviation is [tex]\sigma= \$ 8, 200[/tex]
Given that the confidence interval is 90% then the level of significance is mathematically evaluated as
[tex]\alpha = 100 - 90[/tex]
[tex]\alpha = 10 \%[/tex]
[tex]\alpha = 0.10[/tex]
Next we obtain the critical value of [tex]\frac{ \alpha }{2}[/tex] from the normal distribution table , the value is
[tex]Z_{\frac{\alpha }{2} } = 1.645[/tex]
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \frac{ \sigma }{ \sqrt{n} }[/tex]
=> [tex]E = 1.645 * \frac{ 8200 }{ \sqrt{64} }[/tex]
=> [tex]E = 1686.13[/tex]
The 90% confidence interval is mathematically represented as
[tex]\= x - E < \mu < \= x + E[/tex]
=> [tex]32000 - 1689.13 < \mu < 32000 + 1689.13[/tex]
=> [tex]\$ \ 30313.9< \mu < \$ \ 33686.13[/tex]
-36 4/9 - (-10 2/9) -(18 2/9)
Answer: [tex]-44\dfrac{4}{9}[/tex]
Step-by-step explanation:
The given expression: [tex]-36\dfrac{4}{9}-(-10\dfrac{2}{9})-(18\dfrac{2}{9})[/tex]
Here, [tex]36\dfrac{4}{9}=\dfrac{36\times9+4}{9}=\dfrac{328}{9}[/tex]
[tex](10\dfrac{2}{9})=\dfrac{92}{9}\\\\(18\dfrac{2}{9})=\dfrac{9\times18+2}{9}=\dfrac{164}{9}[/tex]
That is
[tex]-36(\dfrac{4}{9})-(-10\dfrac{2}{9})-(18\dfrac{2}{9}) = -\dfrac{328}{9}-(-\dfrac{92}{9})-\dfrac{164}{9}\\\\=-\dfrac{328}{9}+\dfrac{92}{9}-\dfrac{164}{9}\\\\=\dfrac{-328+92-164}{9}\\\\=\dfrac{-400}{9}\\\\=-44\dfrac{4}{9}[/tex]
Given: f(x) = x + 2 and g(x) = x2 +3, find the following:
28) f(-3)
29) f(g(2))
30) g(f(x))
31) f-1(x)
Answer:
28) -1
29) 9
30) x^2+4x+7
31) x-2
Step-by-step explanation:
Given:
f(x) = x + 2
g(x) = x^2 +3
Find:
28) f(-3)
29) f(g(2))
30) g(f(x))
31) f-1(x)
Solution:
Put the function argument values into the expression and do the arithmetic.
28) f(-3) = (-3) +2 = -1
__
29) f(g(2)) = f((2)^2 +3) = f(7) = (7) +2 = 9
__
30) g(f(x)) = g(x+2) = (x+2)^2 +3 = x^2 +4x +7
__
31) The meaning of y = f^-1(x) is x = f(y).
x = f(y) = y+2
y = x -2
f^-1(x) = x -2
Solve for 2 in the diagram below.
120°
32°
T=
Step-by-step explanation:
Hello, there!!!
It's so simple here,
Here,
we have is 1 angle is 120°and other is 3x°.
now,
3x°=120° {because when two st.line intersects eachother then the opposite angle formed are equal}
so, 3x°=120
or, x=120°/3
=40°
Therefore, the value of x is 40°.
Hope it helps....
Find the number of pieces of floor tiles each measuring 26cm long and 10cm wide needed to lay a floor measuring 260m long and 15m wide
Answer:
150,000
Step-by-step explanation:
1 m = 100 cm
260 m = 260 * 100 cm = 26000 cm
15 m = 15 * 100 cm = 1500 cm
area of floor = LW = 26000 cm * 1500 cm = 39,000,000 cm^2
area of 1 tile = 26 cm + 10 cm = 260 cm^2
number of tiles needed = 39,000,000/260 = 150,000
Answer: 150,000 tiles
