Question 1:
Ho: mu = 6
Ha: mu > 6
xbar= 7.1
pop. sd = 4
n = 14
a) explain what each of the things above are.
b) would you get a z score or a t score? explain how you know
c) use the value you got in part b. to aquire a p value
d) explain in complete sentences what you can say one you have your answer in c.
Question 2: The listed sample distances (in millimeters) was obtained by using a pupilometer to measure the distances between the two pupils for a bunch of adults.
67 66 59 62 63 66 66 55 63 61 60 56 66 67 59 59 60 62 61
a) Give the following information:
xbar
s
n
df
t* or z* (whichever is appropriate) for 90% confidence interval
b) Give a 90% confidence interval for the distances between pupils for the population of all adults.
c) in what ways could you minimize the MOE (if you don't know what the MOE is, use your book)
Question 3:
One of the ways we could do that is to add more people, so that's what were going to do. Here are the pupil distances of more people. (INCLUDE THESE WITH THE NUMBERS WE ALREADY USED)
63 52 57 63 60 64 65 63 64 59 60 60 60 66 56 62 60 62 56 60 60 58 52 54
a) My science book here claims that the distance between pupils is 60 mm for the average adult. We want to see if that's different than the results we got.
b) Set and run either a z.test or a t.test, whichever you deem more appropriate.
c) using your results from b, give me complete, coherent sentences explaining what we know based upon our information.
Question 4:
When 70 convicted embezzlers were randomly selected, the mean length of their prison sentence was found to be 22.1 months and the sd was 8.6 months (from the US DOJ). A governor is running on a platform to be tough on crime; she claims that prison terms for convicted embezzlers on average is under 2 years. Use your knowledge to try and evaluate her claim. Use alpha=0.01 for this question.
a) Run the appropriate tests for this to come to a conclusion. Give me all necessary information.
b) What would have happened if we had used an alpha of 0.05 instead of 0.01? What would have changed?
Question 5:
I claim that my pulse rate is slower than that of all of my students.
a) Set up the following: goal, null and alternate hypothesis, cautions, BASIC procedure.
b) Get some data!
c) run the needed and appropriate tests and write a brief paragraph explaining whether or not you believe my claim to be true.
Question 6:
Here are the IQ test scores of 31 seventh-grade girls in a Midwest school district. This is an SRS over the whole district. The sd of IQ scores is known at 15 for this population.
114 100 104 89 102 91 114 114 103 105 108 130 120 132 111 128 118 119 86 72 111 103 74 112 107 103 98 96 112 112 93
I am curious as to whether these girls could be considered average. State a Ho, a Ha, and go through the proceedings to determine whether or not these girls should be considered average in terms of IQ. (in case you are unaware, 100 is considered average)
Question 7:
In the United States, the mean yield of corn has been 120 bushels per acre. This year, 40 farmers gave their yields, with a mean of 123.8. The average yield has sd of 10 bushels.
a. Assume we want to prove that this sample shows the mean is higher than 120 this year. Write a null and alternative hypothesis.
b. Can you conclude that the mean this year is higher than 120? Show your numbers and explain your reasoning.