Directions: Write a report of your answers on separate sheets of paper, taking care to prepare a legible and organized report. Put your name on your report. Answer questions in order and underline or draw a box around any final numerical answers. Show your work for all answers and include the company name you obtained the data from. Full credit will not be given to answers without work, and partial credit may be given when work is shown. Write any written answers or explanations clearly, and be as neat as possible. You will have to submit your assignment on Canvas. You can embed pictures of your homework in a Word or pdf file. Pro tip: use a scanning app like “Camscanner.” It’s free and it will produce quality pdf files.
- You will need your ticker code (company abbreviation) for stock prices for this question. Use your ticker code to obtain the closing prices for the following two time periods to obtain two data sets:
March 2, 2019 to March 16, 2019 Data set A
February 16, 2019 to February 28, 2019 Data set B
Take the closing prices from data set B and add 0.5 to each one of them.
Treat data sets A and B as hypothetical sample level data on the weights of newborns whose parents smoke cigarettes (data set A), and those whose parents do not (data set B).
- Conduct a hypothesis test to compare the variances between the two data sets.
- Conduct a hypothesis to compare the means between the two data sets. Selecting the assumption of equal variance or unequal variance for the calculations should be based on the results of the previous test.
- Calculate a 95% confidence interval for the difference between means.
- Take data sets A and B and delete duplicated values such that each value is unique even when pooling the two data sets. Just like with the previous problem, treat data sets A and B as hypothetical data on the weights of children whose parents smoke cigarettes, and those whose parents do not, respectively. Conduct a Wilcoxon Rank-Sum test on the data.
- Take the mean and standard deviation of data set A calculated in problem 1 and assume that they are population parameters (μ and σ) known for the variable fish length in a population of rainbow trouts in the Coldwater River. Imagine that data set B is a sample obtained from a different population in Red River (Chapter 6 problem!).
- Conduct a hypothesis test to see if the mean fish length in the Red River population is different from the population in Coldwater River.
- Conduct a hypothesis test to see if the variance in fish length is different in the Red River population compared to the variance in the Coldwater population.
- An experimental drug is being tested to see if it reduces blood sugar in patients suffering from diabetes. Each of seven patients will receive both the placebo and the experimental drugs (treatments given a month apart) for a two week period. The maximum blood sugar (measured every day) on the second week of treatment is recorded. The data obtained from such a study is shown below:
| Patient | Placebo | Exp. Drug | Difference |
| 1 | 125 | 127 | -2 |
| 2 | 130 | 100 | 30 |
| 3 | 133 | 110 | 23 |
| 4 | 122 | 87 | 35 |
| 5 | 150 | 102 | 48 |
| 6 | 156 | 140 | 16 |
| 7 | 145 | 146 | -1 |
| Mean | 137.3 | 116.0 | 21.3 |
| SD | 13.1 | 22.1 | 18.5 |
Conduct a hypothesis test to determine whether the new experimental treatment is beneficial for treating diabetes (reduces blood sugar).
IMPORTANT NOTE: Make sure you do the following:
-State H0 and Ha using notation for each hypothesis test conducted.
-Use α = 0.05 for all hypothesis tests conducted.
-Explain all results obtained for both hypothesis tests and confidence intervals.
-You can use Excel to calculate means and standard deviations but all other calculations have to be done by hand.
