Answer:
Check the explanations
Step-by-step explanation:
According to given information, an instructor at a major research university occasionally teaches summer session and notices that that there are often students repeating the class. On the first day of class, she counts 105 students enrolled, of which 19 are repeating the class. The university enrolls 15,000 students.
Therefore the number of observation n 105 and enrolled x=19
1. An estimate of the population proportion repeating the class is given by:
c) 0.181.
Explanation:
19 --0.18090,181 n 105
2. The instructor wishes to estimate the proportion of students across campus who repeat a course during summer sessions and decides to do so on the basis of this class. Would you advise the instructor against it and why:
d) Yes, because this class is not a random sample of students.
3. The standard error for the estimated sample proportion is given by:
c) 0.0376.
Explanation:
SE [tex](\hat{p})=\sqrt{\frac{\hat{p}(1-\hat{p})}{n}}[/tex]
0.181 × (1-0.181) 105
0,0376 0.0376
4. A 95% confidence interval is given by:
c) 0.107, 0.255.
Explanation:
In order to determine the 95% confidence interval we follow the following step:
Where the z value is determined from the standard normal table as ~ 1.96
[tex]\hat{p}\pm \left [z\times SE(\hat{p}) \right ][/tex]
0.181 ± (1.96 × 0.0376)
0.181 ± 0.0737
Therefore the lower confidence interval is
LCI= 0.181- 0.0737
LCI= 0.107
Therefore the upper confidence interval is
UCI = 0.181 + 0.0737
UCI0.255
Therefore 95% confidence interval is
[tex]\left (0.107,0.255 \right )[/tex]
5. She hypothesizes that, in general, 10% of students repeat a course. The hypotheses to be tested are:
d)[tex]0 :P = 0.10 and H_{a}:p\neq 0.10[/tex]
Explanation:
She hypothesizes that, in general, 10% of students repeat a course. The hypotheses to be tested are defined on the basis of observation,
Null hypothesis as:
[tex]H_{0}[/tex]:p= 0.10
and alternative hypothesis as:
[tex]H_{a}:p\neq 0.10[/tex]
6. The test statistic for this hypothesis is given by:
c) 2.765.
Explanation:
In order to determine the z test statistics as:
Z=[tex]\frac{\hat{p}-p_{0}}{\sqrt{\frac{p_{0}(1-p_{0})}{n}}}[/tex]
0.181 - 0.10 0.10x (1-0.10)
=2.765
7. The P value for this test is:
c) 0.01>P>0.005 .
Explanation:
P value is calculated as:
P(Z > 2.765) 0.002845 for one tail test and
P(Z > 2.765) 0.005692 for two tail test.
8. Based on the p-value found:
b) we have strong evidence that the proportion of students repeating a class during summer sessions is not 10%.
Explanation:
As the z observed is more than the tabulated z value at 95% as:
[tex]Z_{observed}=2.765> Z_{tabulated}=1.96[/tex]
and also P value is less than the [tex]\alpha =1-0.95=0.05[/tex]
[tex]P(Z\geq 2.765)=0.005692< \alpha =0.05[/tex]
Therefore we accept the alternative hypothesis and we may conclude that we have strong evidence that the proportion of students repeating a class during summer sessions is not 10%.
a bacteria population is 10,000. it triples each day. The bacteria population. p, is a function of the number of days, d.
A. p(d) = 10000(3)d
B. d(p) = 10000(3)p
C. p(d) = 3(10000)d
D. p(d) = 3(10000)p
Answer: D. p(d) = 3(10000)p
Step-by-step explanation:
The function is p(d) = 3(10000)p, where p is the bacteria population and the number of days, d. The correct answer would be option (D).
What are the functions?The function is defined as a mathematical expression that defines a relationship between one variable and another variable.
As per the given situation, we can write the function would be as:
⇒ p(d) = 3(10000)p
It states that the population of the bacteria, p, is equal to the starting population of 10,000 multiplied by 3 number of days, d. This function correctly represents the idea that the population triples each day.
Hence, the correct answer would be an option (D).
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Nora made 15 gallons of lemonade for a community picnic.
Part A
Which of the following can be used to find the number of pints of lemonade that Nora made?
15 × 2 × 2
15 × 4 × 2
15 × 3 × 2
15 × 4 × 3
Part B
How many pints of lemonade did Nora make?
Enter your answer in the box.
pints
Answer:
I also belive for Part A the second one is the answer because it equals 120 Part B is 120 pints! Good Luck! And I hope this Helps!
Answer:
B
Step-by-step explanation:
Two squares are similar. The first square has sides that measure 4 inches, and the second squares has sides that measure 12 inches. The scar factor used to get from the first square to the second one is
Answer:
3
Step-by-step explanation:
Well, first off I'm assuming that by "scar factor" you mean scale factor. So if the two squares are similar then that means the sides are also similar, that means that they are equivalent. So all you have to do is 12/4 to get 3. So then to check it, you do 4 times 3 which gets you to 12.
So the final answer is 3
Triangles BAD and BDC are right triangles with AB = 12 units, BD = 15 units, and $BC = 17 units. What is the area, in square units, of quadrilateral ABCD?
Answer:
The area of the quadrilateral ABCD is 114 square units
Step-by-step explanation:
We must calculate the area of each triangle and then add these areas so we calculate the area of the quadrilateral ABCD
First for the BAD right triangle:
AD = sqrt [BD ^ 2 - AB ^ 2]
AD = sqrt [15 ^ 2 - 12 ^ 2]
AD = sqrt [225-144]
AD = sqrt [81]
AD = 9
The area of a triangle is half the product of the base times the height, that is:
A1 = AB * AD / 2 = 12 * 9/2 = 54
Then for the second triangle in the right triangle BDC:
DC = sqrt [BC ^ 2 - BD ^ 2]
DC = sqrt [17 ^ 2 - 15 ^ 2]
DC = sqrt [289 - 225]
DC = sqrt [64] = 8
We calculate the area
A2 = DC * BD / 2 = 8 * 15/2 = 60
The total area then is:
AT = A1 + A2
AT = 54 + 60 = 114
Which means that the area of the quadrilateral ABCD is 114 square units
The tuition at a college was $30,000 in 2012, $31,200 in 2013, and $32,448 in 2014. The tuition has been increasing by the same percentage since the year 2000.
The equation C(T) = LaTeX: 30000\cdot1.04^T
30000
⋅
1.04
T
represents the cost of tuition, in dollars, as a function of T, the number of years since 2012. Explain what the 30,000 and 1.04 tell us about this situation.
What is the percent increase in tuition from year to year?
What does C(3) mean in this situation? Find its value and show your reasoning.
a. Write an expression to represent the cost of tuition in 2007.
b. How much did tuition cost that year?
Previous Next
The meaning of each parameter is given as follows:
30,000: cost in the reference year of 2012.1.04: rate of change.Then the yearly percent increase is of:
4%.
C(3) represents the cost in 2015, which was of $33,746.
a) The expression to represent the cost in 2007 is of: C(-5).
b) The cost was of: $24,658.
How to define an exponential function?An exponential function is defined as follows:
y = ab^x.
In which:
a is the initial value.b is the rate of change.For this problem, the function is defined as follows:
y = 30000(1.04)^x.
In which:
x is the number of years since 2012.y is the cost in x years after 2012.C(3) represents the cost in 2015 and is obtained as follows:
C(3) = 30000(1.04)^3 = $33,746.
C(-5) represents the cost in 2007 and is obtained as follows:
C(-5) = 30000(1.04)^(-5) = $24,658.
(as 2007 was five years before 2012).
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What is the simplest form of this expression?
(2x + 1)(x2 - 9X+11)
Answer:
2x³ - 17x² + 13x + 11
Step-by-step explanation:
(2x + 1)(x² - 9x + 11) Distribute the 2x then the 1
2x³ - 18x² + 22x + x² - 9x + 11 Combine like terms
2x³ - 17x² + 13x + 11
If this answer is correct, please make me Brainliest!
¿1 y media taza x 9?
Answer: [tex]1\frac{1}{2} *9=\frac{3}{2}*9=\frac{27}{2}=13\frac{1}{2}[/tex]
Step-by-step explanation:
Answer: 27
-------
2
Step-by-step explanation:
Connor is 4 2/3 feet tall. How many inches is that?
Answer:
hes
56 inches
hope it helps
Please help ASAP! I will mark Brainliest! Please answer CORRECTLY! No guessing!
Answer:
D is The correct Answer
Step-by-step explanation:
Answer:
d I'm sorry if its incorrect
A project is found to have expected time T = 35.33 days and variance V = 3.22.
a. What value of z is needed to find the probability that the project will take at least 40 days? (round final answer to 2 decimals as needed)
b. What value of z is needed to find the probability that the project will take at most 40 days? (round final answer to 2 decimals as needed)
c. What value of z is needed to find the probability that the project will take at most 30 days? (round final answer to 2 decimals as needed)
Answer:
a) [tex] z = \frac{40-35.33}{1.794}= 2.60[/tex]
b) [tex] z = \frac{40-35.33}{1.794}= 2.60[/tex]
c) [tex] z = \frac{30-35.33}{1.794}= -2.97[/tex]
Step-by-step explanation:
For this case we know that the mean for the random variable of interest is [tex]\mu = 35.33[/tex] and the variance [tex]\sigma^2 = 3.22[/tex] so then the deviation would be [tex]\sigma = \sqrt{3.22}= 1.794[/tex]
The z score is given by thsi formula:
[tex] z = \frac{X -\mu}{\sigma}[/tex]
Part a
We want this probability:
[tex] P(X>40)[/tex]
And if we find the z score we got:
[tex] z = \frac{40-35.33}{1.794}= 2.60[/tex]
And we can find this probability: [tex] P(Z>2.60)[/tex]
Part b
We want this probability:
[tex] P(X<40)[/tex]
And if we find the z score we got:
[tex] z = \frac{40-35.33}{1.794}= 2.60[/tex]
And we can find this probability: [tex] P(Z<2.60)[/tex]
Part c
We want this probability:
[tex] P(X<30)[/tex]
And if we find the z score we got:
[tex] z = \frac{30-35.33}{1.794}= -2.97[/tex]
And we can find this probability: [tex] P(Z<-2.97)[/tex]
The area of a rectangular wall of a barn is 171 square feet . It’s length is 10 feet longer than the width . Find the length and width of the wall of the barn
Answer:
10 x 17.1 = 171
Step-by-step explanation:
10 x 17.1 = 17.1
During one year Saul takes 15 credit hours for each three quarters. Tuition and fees amount to $608 per credit hour. Textbooks average $420 per quarter. The prorated monthly cost for tuition and fees and textbooks is?
Answer:
Total textbook cost of tuition fees per month will be $ 2,356 and 25 cents
Step-by-step explanation:
To solve the exercise, we will first define the total cost per quarter.
cost of 1 credit hour = $ 601
then we solve the following:
cost of 15 credit hours = $ 601 * 15 = $ 9015
textbooks = $ 410
then we solve the following:
total cost = 9015 + 410 = $ 9425
total cost for 3 quarters = 3 * $ 9425 = $ 28275 for 12 months
we calculate as follows
Total textbook cost of tuition fees per month will be
$ 28,275 / 12 = $ 2,356 and 25 cents
Jakob is asked to simplify the expression –3a + 4b + 5a + (–7b).
He writes: –3a + 4b + 5a + (–7b) = –3a + 5a + 4b + (–7b).
Which property allows him to do this?
the associative property
the commutative property
the distributive property
the additive identity property
Answer: b commutative property
Step-by-step explanation: idid the test and i got it right
The property of algebra that allowed jakob simplify the given expression as stated is called; B: The commutative Property
What is a commutative Property?She wants to simplify the expression -3a + 4b + 5a + (-7b)
Now, there are different properties of algebra but the one that jakob used here is called commutative property of algebra.
Commutative property is expressed as an example like;
a + b = b + a
Thus, using commutative property, he arrived at –3a + 4b + 5a + (–7b) = –3a + 5a + 4b + (–7b).
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Which equation represents the black line?
Which equation represents the red line?
Explain a mathematical way to find the intersection of the lines without actually graphing the lines.
Answer:
Black Line y = 3 + 2x , y = 2x +3
Red Line y = -2 - .5x. y = -.5x -2
vice versa
Step-by-step explanation:
For the black line, the lines intersects y at coordinate (0,3) and that would be b. To find the slope, use the equation rise / run. It rises 4 and runs 2. Putting this into an equation 4/2, it would be 2 as the constant. In other words, it would be 2x. Therefore, the function for the black line is y = 3 + 2x
For the red line, using the same explanation from the black line, the line intersects y at -2, and the slope would be -.5x, since it runs downwards 2 and runs 4, and since it runs downwards, a negative sign would be necessary in front of the slope.
the sum of three consecutive numbers is 114 . what is the smallest of these numbers
Answer:
x + (x+1) + (x+2) = 114
3x = 111
x = 37
the numbers are 37, 38 and 39
the smallest number is 37
Step-by-step explanation:
1).
A) supplementary
B) complementary
C) comesponding
D) alternate interior
Which equation represents the hyperbola shown in the
graph?
10
8
(x - 2)2
(y + 3)
25
(-2,5) 6
(-7,3)
(1-21)
4-12-10 -8 -6 4-2
(3,3)
(x + 2)2
(y = 3) = 1
4
2 4 6
(x + 2)2
25
(y - 3)2
4
1
(232) - (7,31 = 1
(x - 2)2
25
Answer:
Step-by-step explanation:
A general equation of a hyperbola is
x^2 y^2
-------- - ------- = 1 (This applies only when the center of the hyperbola
a^2 b^2 is at (0, 0) ).
You must compare the given equations to this standard form to identify which represents the hyperbola shown, and also you must share the illustration of the hyperbola.
The equation represents the hyperbola shown in the graph is (y - 1)² / 9 - (x + 4)² / 4 = 1
What is a hyperbola?A hyperbola is a type of smooth curve lying in a plane, defined by its geometric properties or by equations for which it is the solution set.
A hyperbola has two pieces, called connected components or branches, that are mirror images of each other and resemble two infinite bows.
Given that, a graph, showing hyperbola, we need to find the equation,
We have the general equation for up - down facing hyperbola as
(y - k)² / b²- (x - h)² / a² = 1.
Let's start listing the properties of this graph -
Taking a look at the graph we see that the center point of our hyperbola here is (- 4, 1).
Therefore, (h, k) = (- 4,1).
This is the semi distance from the center to one of the vertices. Here it will be the distance from points (- 4,1) and (- 4,4) or 3 unit difference.
Therefore, a = 3.
That gives asymptotes. Now remember that it will be in the form
y = ± b / a.
We already know a = 3, so we have to find b.
Looking at this graph we can say that another point besides (- 4,1) that lies on the "dotted line" is (- 2, - 2).
Calculating the slope of the dotted line would be as follows,
Given: (- 4,1) and (- 2, - 2)
Slope = - 2 + 4 / - 2 - 1 = 2 / 3
We have the equation y = 2 / 3x.
Therefore, b = 2.
Let's substitute to equation...
h = - 4, k = 1, b = 2, a = 3
(y - 1)² / (3)²- (x + 4)² / (2)² = 1
(y - 1)² / 9 - (x + 4)² / 4 = 1
Hence, the equation represents the hyperbola shown in the graph is (y - 1)² / 9 - (x + 4)² / 4 = 1
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The complete question is attached
How many solutions does the equation -2a + 2a + 7 = 8 have
Step-by-step explanation:
-2a + 2a + 7 = 8
Solving like terms
7 = 8
= 8 - 7 = 1
Has one solution
Determine the intercepts of the line. y=6x+13y=6x+13
Answer:
x-intercept: -13/6
y-intercept: 13
General Formulas and Concepts:
Algebra I
Equality Properties
Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of EqualityCoordinate Planes
The y-intercept is the y value when x = 0. Another way to reword that is when the graph crosses the y-axis. The x-intercept is the x value when y = 0. Another way to reword that is when the graph crosses the x-axis.Slope-Intercept Form: y = mx + b
m - slope b - y-interceptTerms/Coefficients
Step-by-step explanation:
Step 1: Define
Identify.
y = 6x + 13
Step 2: Find y-intercept
Compare given equation to slope-intercept form.
y = 6x + 13 ↔ y = mx + b
Slope m = 6
y-intercept b = 13
Step 3: Find x-intercept
Substitute y = 0.
Substitute in y [Equation]: 0 = 6x + 13[Subtraction Property of Equality] Subtract 13 on both sides: -13 = 6x[Division Property of Equality] Divide 6 on both sides: -13/6 = xRewrite: x = -13/6Jacqueline wants to make as many identical bouquets as possible using all flowers she has. What is the biggest number of such bouquets can be made out of 42 carnations, 36 tulips and 54 daffodils?
Answer:
6
Step-by-step explanation:
The greatest common factor of 36, 42, and 54 is 6:
36 = 6·6
42 = 6·7
54 = 6·9
Jacqueline's bouquets will have 6 tulips, 7 carnations, and 9 daffodils in each one. There will be 6 bouquets.
A bag of colored marbles contains 16 blue marbles, 12 red marbles, and 8 yellow marbles.
What is the theoretical probability of drawing a red marble?
Enter your answer as a reduced fraction, like this: 3/14
Answer:
The theoretical probability of drawing a red marble is 1/3.
Step-by-step explanation:
1. Add all of the marbles together to get total marbles. 16 + 12 + 8 = 36.
2. Create a fraction, with numerator being favorable outcomes and denominator being total possible outcomes. In this case it would be 12/36.
3. Since it is asking for a reduced fraction, simplify 12/36 to 1/3.
The rectangle shown is dilated by a scale factor of 1/5
What is the length of side A'B' and side B'D'?
Answer:
A'B'= 3 cm and B'D' = 1.6 cm
Step-by-step explanation:
First of all, we are told that the scale factor = 1/5
Now,we know that If the scale factor is less than 1, then the dilation is a reduction.
Thus, in this question the dilation is a reduction.
For us to calculate the dimensions of the dilated rectangle, we'll multiply the original dimensions by the scale factor
Thus;
A'B' = AB(1/5)
A'B' = 15(1/5) = 3 cm
B'D' = BD(1/5) = 8(1/5) = 1.6 cm
Thus, The length of each side of the dilated rectangle are;
A'B'= 3 cm and B'D' = 1.6 cm
For the data 20, 40, 50, 20, 10, 70. What is there mean absolute deviation?
Answer:
18.333
Step-by-step explanation:
Given two independent random samples with the following results: n1=8x‾1=186s1=33 n2=7x‾2=171s2=23 Use this data to find the 90% confidence interval for the true difference between the population means. Assume that the population variances are equal and that the two populations are normally distributed. Step 1 of 3: Find the point estimate that should be used in constructing the confidence interval.
Answer:
The point of estimate for the true difference would be:
[tex] 186-171= 15[/tex]
And the confidence interval is given by:
[tex] (186-171) -1.77 \sqrt{\frac{33^2}{8} +\frac{23^2}{7}}= -10.753[/tex]
[tex] (186-171) +1.77 \sqrt{\frac{33^2}{8} +\frac{23^2}{7}}= 40.753[/tex]
Step-by-step explanation:
For this case we have the following info given:
[tex] \bar X_1 = 186[/tex] the sample mean for the first sample
[tex] \bar X_2 = 171[/tex] the sample mean for the second sample
[tex]s_1 =33[/tex] the sample deviation for the first sample
[tex]s_2 =23[/tex] the sample deviation for the second sample
[tex]n_1 = 8[/tex] the sample size for the first group
[tex]n_2 = 7[/tex] the sample size for the second group
The confidence interval for the true difference is given by:
[tex] (\bar X_1 -\bar X_2) \pm t_{\alpha/2}\sqrt{\frac{s^2_1}{n_1} +\frac{s^2_2}{n_2}}[/tex]
We can find the degrees of freedom are given:
[tex] df = n_1 +n_2 -2 =8+7-2= 13[/tex]
The confidence level is given by 90% so then the significance would be [tex]\alpha=1-0.9=0.1[/tex] and [tex]\alpha/2=0.05[/tex] we can find the critical value with the degrees of freedom given and we got:
[tex] t_{\alpha/2}= \pm 1.77[/tex]
The point of estimate for the true difference would be:
[tex] 186-171= 15[/tex]
And replacing into the formula for the confidence interval we got:
[tex] (186-171) -1.77 \sqrt{\frac{33^2}{8} +\frac{23^2}{7}}= -10.753[/tex]
[tex] (186-171) +1.77 \sqrt{\frac{33^2}{8} +\frac{23^2}{7}}= 40.753[/tex]
Choose the inequality that represents the following graph
Answer:
X ≥ 3 (D)
Step-by-step explanation:
I got it right on Khan Academy :)
A bike tire has a diameter of 16 inches. What is the radius of the bike? What is the circumference of the bike?
Answer:
radius-8 inches cause math
circumference-50.27
Step-by-step explanation:
Solve the system of equations using the elimination method 4x+5y=40 6x+3y=42
Answer:
The solutions to the system of equations are [tex]y=4,\:x=5[/tex].
Step-by-step explanation:
To solve the system [tex]\begin{bmatrix}4x+5y=40\\ 6x+3y=42\end{bmatrix}[/tex]
First,
[tex]\mathrm{Multiply\:}4x+5y=40\mathrm{\:by\:}3\:\mathrm{:}\:\quad \:12x+15y=120\\\\\mathrm{Multiply\:}6x+3y=42\mathrm{\:by\:}2\:\mathrm{:}\:\quad \:12x+6y=84[/tex]
[tex]\begin{bmatrix}12x+15y=120\\ 12x+6y=84\end{bmatrix}[/tex]
Subtract the first equation from the second equation
[tex]12x+6y=84\\\underline{-12x-15y=-120}\\-9y=-36[/tex]
Solve [tex]-9y=-36[/tex] for y:
[tex]\frac{-9y}{-9}=\frac{-36}{-9}\\y=4[/tex]
For [tex]12x+15y=12[/tex] plug in [tex]y=4[/tex] and solve for x
[tex]12x+15\cdot \:4=120\\12x=60\\x=5[/tex]
The solutions to the system of equations are:
[tex]y=4,\:x=5[/tex]
According to a Pew Research Center report from 2012, the average commute time to work in California is 27.5 minutes. To investigate whether the small city she lives in has a different average, a California high school student surveys 45 people she knows (her teachers, her parents, and their friends and co-workers) and finds the average commute time for this sample to be 24.33 minutes with a standard deviation of 9.53 minutes. The data are not too skewed. The null and alternative hypotheses of her study are: H0 : µ = 27.5 versus Ha : µ 6= 27.5
Required:
a. Identify the observational units for this study.
b. Identify the variable of interest and state whether it is categorical or quantitative.
c. Identify (in words and using an appropriate symbol) the parameter of interest
d. Use the 2SD approach to find a 95% confidence interval for the parameter.
e. Interpret the interval from part d. in context.
Solve the inequality
Math question
Answer:
AAAAAAAAAAAAAAAAAAAA
Step-by-step explanation:
x < 7
1. 10(.15)=1.5
2. 10-1.5=8.5
3. 8.5 (.15)=1.275
4. 8.5-1.275=7.225
Keep going until you get number 5 and below 1
!!!!!!!!!!!!!!!!!!!!!!!!
PLEASE MAN!
Answer:
6.14125(0.15) = 0.9211875 (below 1)
6.14125 - 0.92118 = 5.22007
Step-by-step explanation:
Given data
1. 10(.15)=1.5
2. 10-1.5=8.5
3. 8.5 (.15)=1.275
4. 8.5-1.275=7.225
continuation the sequence
5) 7.225 (0.15) = 1.08375
6) 7.225 - 1.08375 = 6.14125
7) 6.14125(0.15) = 0.9211875 (below -one)
8 ) 6.14125 - 0.9211875 = 5.2200625 (get number 5)
9) 5.2200625(0.15) = 0.783009
10) 5.2200625 - 0.783009 = 4.4370532
