Use data from Excel to complete problems 3.1 and 3.2. When you open the file look at the tabs on the bottom left. You will use the data from the “Class_LabScores” tab to answer these questions.
Frequency distribution tables for Dr. Wallace's three statistics courses  
X = quiz scores  
Class 1  Class 2  Class 3  
X  f  X  f  X  f  
0  3  0  0  0  3  
1  0  1  0  1  0  
2  0  2  0  2  1  
3  2  3  3  3  0  
4  3  4  2  4  0  
5  6  5  1  5  2  
6  4  6  2  6  3  
7  2  7  0  7  1  
8  3  8  4  8  1  
9  2  9  2  9  0  
10  1  10  3  10  0  
11  4  11  4  11  2  
12  3  12  3  12  4  
13  8  13  6  13  6  
3.1. Dr. Wallace teaches three statistics labs at three different times of day (1  morning, 2  noon, 3  night). She is curious to find out whether or not time of day is related to student scores on the lab assignments. Frequency distribution tables for each of her three lab classes appear on the “Class_LabScores” tab in the Excel file. Please calculate the following:
Mean for Morning Class 1:
Mean for Noon Class 2:
Mean for Night Class 3:
3.2 Dr. Wallace is preparing a summary of her teaching experience in the statistics lab classes. She only wants to use one number to represent student performance in those classes, so she’ll need to calculate one mean. In addition, she wants to be fair and make sure that every student’s lab score contributes equally to the overall mean. In order to do this, she needs to calculate the weighted mean. Please calculate the following and show work:
Weighted mean for her statistics classes:
In: Math
The objective of the question is to test the Hypothesis If the Mean travel time in minutes between Point A to Point B is equal to the mean of the travel time in minutes from Point B to your A. First you must find the mean and standard deviations. Then perform and list the complete required steps for the TWO required Hypothesis tests and use the PValue as a rejection Rule for both tests.
One Hypothesis test is an F test for the equality of the variances of travel Times and the second test is a T test for the equality of the means of travel times in minutes. The F test must be performed first in order to select either Case1 or Case 2 for the Ttest.
Recorded Time values in minutes from point A to point B in minutes: 32, 34, 51, 30, 29, 35, 36, 29, 32, 29, 33, 32, 29, 30, 33, 30, 30, 33, 30, 31, 35, 35, 34, 33, 31, 34, 30, 30, 29, 34, 32, 35, 29, 30, 32, 30, 33, 31
n_{A}=38
Recorded Time values in minutes from point B to point A in minutes: 36, 28, 48, 28, 27, 54, 34, 29, 26, 34, 33, 42, 29, 34, 31, 4, 27, 42, 28, 45, 26, 43, 32, 30, 27, 29, 29, 35, 26, 31, 28, 27, 28, 32, 41, 34, 28, 31
n_{B}=38
In: Math
Describe some of the benefits of using a survey design in quantitative research.
In: Math
Background: This activity is based on the results of a recent study on the safety of airplane drinking water that was conducted by the U.S. Environmental Protection Agency (EPA). A study found that out of a random sample of 316 airplanes tested, 40 had coliform bacteria in the drinking water drawn from restrooms and kitchens. As a benchmark comparison, in 2003 the EPA found that about 3.5% of the U.S. population have coliform bacteriainfected drinking water. The question of interest is whether, based on the results of this study, we can conclude that drinking water on airplanes is more contaminated than drinking water in general.
Question 1: (Remember write all answer in an MS Word doc and upload)
Let p be the proportion of contaminated drinking water in airplanes. Write down the appropriate null and alternative hypotheses.
Question 2:
Based on the collected data, is it safe to use the ztest for p in this scenario? Explain.
Use the following instructions to conduct the ztest for the population proportion:
Instructions  2 Options
Option 1: Click on the following link to use the MS Excel
hypothesis test template: hypothesis.xls
R  StatCrunch  Minitab  Excel 2007  TI Calculator
Question 3:
Now that we have established that it is safe to use the Ztest for p for our problem, go ahead and carry out the test. Paste the output below.
Question 4:
What is the test statistic for this test? (Hint: Calculation already done by either technology option.) Interpret this value.
Question 5:
What is the PValue? Interpret what that means, and draw your conclusions. Assume significance level of 0.05.
In: Math
An animal’s maintenance caloric intake is defined as the number of calories per day required to maintain its weight at a constant value. We wish to discover whether the median maintenance caloric intake, m, for a population of rats is less than 10g/day. We draw a SRS of 17 rats, feed each rat 10g of dry food per day for30 days, and find that 4 of the rats lost weight, while the rest gained weight.
(a) State null and alternative hypotheses in terms of m.
(b) Let B be the number of rats in a SRS of size 17 that exhibit daily caloric demands more than 10g/day.IfH0is true, what is the distribution ofB?
(c) What is the value of B observed in the study?
(d) Use the sign test to calculate the pvalue and draw a conclusion using α= 0.05.
In: Math
In a timeuse study, 20 randomly selected college students were
found to spend a mean of 1.4 hours on the internet each day. The
standard deviation of the 20 scores was 1.3 hours.
Construct a 90% confidence interval for the mean time spent on the
internet by college students. Assume t* = 1.729
If you increased the sample size for the problem above, what would
happen to your confidence interval, assuming the sample mean and
standard deviation remain unchanged?
In: Math
A study is conducted regarding shatterproof glass used in automobiles. Twentysix glass panes are coated with an antishattering film. Then a 5pound metal ball is fired at 70mph at each pane. Five of the panes shatter. We wish to determine whether, in the population of all such panes, the probability the glass shatters under these conditions is different from π= 0.2
(a) State the appropriate null and alternative hypotheses.
(b) Check the conditions for trusting the conclusion of the test, and calculate the observed value of an appropriate test statistic.
(c) Calculate the rejection region and draw a conclusion, given the significance level α= 0.05.
(d) Calculate the pvalue.
(e) Compute the power of the test if the trueπwas in fact 0.3.
In: Math
W72A) I am learning EXCEL Functions. Please answer in EXCEL Functions in detail
Stock Returns (relationship between hypothesis testing and confidence intervals)
Suppose you as an investor with a stock portfolio of hundreds of thousands of dollars decide to sue your broker because of low returns due to lack of portfolio diversification, i.e., too many holdings with similar return prospects. The 39 monthly returns, expressed as percentages, are shown in the table below and reproduced in your Excel answer template.
8.36 
1.63 
2.27 
2.93 
2.70 
2.93 
9.14 
2.64 
6.82 
2.35 
3.58 
6.13 
7.0 
15.25 
8.66 
1.03 
9.16 
1.25 
1.22 
10.27 
5.11 
0.80 
1.44 
1.28 
0.65 
4.34 
12.22 
7.21 
.09 
7.34 
5.04 
7.24 
2.14 
1.01 
1.41 
12.03 
2.56 
4.33 
2.35 
If we graph these data in a histogram, we can reasonably infer that the data are distributed normally.
Suppose you’re on an arbitration panel reviewing this case and decide to compare these returns with the Standard & Poor’s (S&P’s) stock index over the same period and find that the S&P mean, which we can interpret as the population mean (μ), equals .95%.
Remember: since we must compute the sample standard deviation, use the tstatistic to perform the test.)
using the data given in the Table above for α = .05. (Express the results with three decimal places, one more than given in the data.) Does the S&P mean lie in the interval you’ve computed?
In: Math
The mean pay in 2008 Bh CEOsat the 500 biggest U.S. companies was 12.8 million dollars.”” Public outcry and stockholder complaints have forced compensation committees to reconsider senior executive salaries. A random sample of CEOs was obtained, and the total pay (in millions of dollars) for each is given in the following table.
10.1 4.3 13.8 5.1 13.0 21.2 4.5 10.5 17.6 10.1 6.5 9.9 13.3 20.4
Is there any evidence to suggest that the mean pay for CEOs has decreased? Use a = 0.05 and assume normality.
In: Math
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STAT 213 Assignment 3: Problem 5
Previous Problem Problem List Next Problem
(1 point)
To examine the effectiveness of its four annual advertising promotions, a mail order company has sent a questionnaire to each of its customers, asking how many of the previous year's promotions prompted orders that would not have otherwise been made. The accompanying table lists the probabilities that were derived from the questionnaire, where X is the random variable representing the number of promotions that prompted orders. If we assume that overall customer behavior next year will be the same as last year, what is the expected number of promotions that each customer will take advantage of next year by ordering goods that otherwise would not be purchased?
X  0  1  2  3  4 
P(X)  0.072  0.221  0.347  0.176  0.184 
Expected value =
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A previous analysis of historical records found that the mean value of orders for promotional goods is 35 dollars, with the company earning a gross profit of 22% on each order. Calculate the expected value of the profit contribution next year.
Expected value =
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The fixed cost of conducting the four promotions is estimated to be 17000 dollars with a variable cost of 2 dollars per customer for mailing and handling costs. What is the minimum number of customers required by the company in order to cover the cost of promotions? (Round your answer to the next highest integer.)
Breakeven point =
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Equation Editor
In: Math
1. The table below contains pricedemand and total cost data for the production of projectors, where p is the wholesale price (in dollars) of a projector for an annual demand of x projectors and C is the total cost (in dollars) of producing x projectors.
x1  p  c 
1943  1035  900 
3190  581  1130 
4570  405  1241 
6490  124  1800 
7330  85  1620 
PriceDemand:
a. Make a scatter plot for p vs x (pricedemand plot).
b. Get a regression line that best fits the data in Question a. You need to type the equation of this line in desmos and graph it with your scatter plot. Please use p(?1) = equation when typing in desmos.
c. Does it look like the regression line models the data well? (Yes or No) Why?
d. Use the equation typed in desmos to find p(0), p(3000), p(6000) 5. What value of x would make p(x) = 0?
In: Math
1.Crop rotation is a common strategy used to improve the yields of certain crops in subsequent growing seasons. An experiment was performed to assess the effects of crop rotation plant type and crop rotation plant density levels on the yield of corn, the primary crop of interest. A field was separated into 12 plots and each of the treatments was randomly applied. After 2 months of growth of the rotated crops, the plots were cleared, and corn seeds were applied evenly to each plot. After 5 months of growth of the corn, the yields were assessed. The data, in kg/m2, are shown below. Determine if crop rotation plant type and density affect the yields of corn in this field. What treatment should the farmers use to maximize the yield?
Density (k/ha) 

Rotation Variety 
05 k/ha 
10 k/ha 
15 k/ha 
20 k/ha 
Pea 
7.8 
11.2 
18.5 
15.4 
9.1 
12.7 
16.7 
14.7 

10.6 
13.3 
15.4 
11.3 

Soy 
7 
9.3 
13.8 
11.3 
6.7 
10.9 
14.3 
12.7 

8.1 
11.8 
15.4 
14.3 

Wheat 
6.4 
4.9 
3.6 
2.8 
4.5 
7.1 
3.9 
6.1 

5.9 
3.2 
5.8 
4.6 
In: Math
For each of the different confidence levels given below determine the appropriate z* to use to create a confidence interval for the population proportion. (Give the positive z* value, rather than the negative.)
C= 88%, z*=
C= 93%, z*=
C= 72%, z*=
In: Math
The heat evolved in calories per gram of a cement mixture is approximately normally distributed. The population mean is thought to be 100, and the population standard deviation σ is 2. You wish to test H0 : µ = 100 versus H1 : µ 6= 100. Note that this is a twosided test and they give you σ, the population standard deviation. (a) State the distribution of X¯ assuming that the null is true and n = 9.
(b) Find the boundary of the rejection region for the test statistic (these critical values will be zvalues) if the type I error probability is α = 0.01.
(c) Find the boundary of the rejection region in terms of ¯x if the type I error probability is α = 0.01. In other words, how much lower than 100 must X¯ be to reject and how much higher than 100 must X¯ be to reject. You will have an ¯xlow and an ¯xhigh defining the rejection region. HINT: You are unstandardizing your z from part (b) here.
(d) What is the type I error probability α for the test if the acceptance region for the hypothesis test is instead defined as 98.5 ≤ x¯ ≤ 101.5? Recall that α is the probability of rejecting H0 when H0 is actually true.
In: Math
The following table shows age distribution and location of a random sample of 166 buffalo in a national park.
Age  Lamar District  Nez Perce District  Firehole District  Row Total 
Calf  14  14  13  41 
Yearling  12  9  12  33 
Adult  30  28  34  92 
Column Total  56  51  59  166 
Use a chisquare test to determine if age distribution and location are independent at the 0.05 level of significance.
(a) What is the level of significance?
State the null and alternate hypotheses.
H_{0}: Age distribution and location are not
independent.
H_{1}: Age distribution and location are not
independent.H_{0}: Age distribution and location
are independent.
H_{1}: Age distribution and location are
independent. H_{0}: Age
distribution and location are not independent.
H_{1}: Age distribution and location are
independent.H_{0}: Age distribution and location
are independent.
H_{1}: Age distribution and location are not
independent.
(b) Find the value of the chisquare statistic for the sample.
(Round the expected frequencies to at least three decimal places.
Round the test statistic to three decimal places.)
Are all the expected frequencies greater than 5?
YesNo
What sampling distribution will you use?
uniformchisquare normalStudent's tbinomial
What are the degrees of freedom?
(c) Find or estimate the Pvalue of the sample test
statistic. (Round your answer to three decimal places.)
pvalue > 0.1000.050 < pvalue < 0.100 0.025 < pvalue < 0.0500.010 < pvalue < 0.0250.005 < pvalue < 0.010pvalue < 0.005
(d) Based on your answers in parts (a) to (c), will you reject or
fail to reject the null hypothesis of independence?
Since the Pvalue > α, we fail to reject the null hypothesis.Since the Pvalue > α, we reject the null hypothesis. Since the Pvalue ≤ α, we reject the null hypothesis.Since the Pvalue ≤ α, we fail to reject the null hypothesis.
(e) Interpret your conclusion in the context of the
application.
At the 5% level of significance, there is sufficient evidence to conclude that age distribution and location are not independent.At the 5% level of significance, there is insufficient evidence to conclude that age distribution and location are not independent.
In: Math