Due Sunday, November 11 th
1.
The Bayley Scales of Infant Development yield scores on two indices – the Psychomotor
Development Index (PDI) and the Mental Development Index (MDI). These can be used to assess a child’s level of function in each of these areas at approximately one year of age.
Among healthy infants, both indices have a mean value of 100. As part of the study assessing the development and neurologic status of children who have undergone reparative heart surgery during the first three months of life, the Bayley Scales were administered to a random sample of 144 one-year-old infants born with congenital heart disease.
The file PDI_MDI.JMP
contains data collected on the following variables:

PDI = psychomotor development index

MDI = mental development index
Research Question: Is there evidence that children born with congenital heart disease who undergo reparative heart surgery during the first three months of life have a mean PDI score less than 100 (which is the mean for healthy infants)? a.
Use JMP to find both the mean and the standard deviation of the PDI and MDI scores.
Enter these values in the following table. (2 pts)
Variable Mean Standard Deviation
PDI
MDI b.
Is the t-test an appropriate analysis procedure for these data? (1 pt)

c.
Set up the null and alternative hypotheses to test the research question. State them in words and using statements about  . (3 pts.)
H o
:
H a
: d.
Find the p-value to test the research question. (1 pt) p-value: _________________________ e.
Write a conclusion to address the research question in the context of the problem. (2 pts) f.
Use JMP to find the 95% CI for the mean PDI score for children born with congenital heart disease who undergo reparative heart surgery during the first three months of life.
Interpret this interval. (3 pts) g.
Does this interval agree with your conclusion given in part e? Explain your reasoning.
(2 pts.) h.
Next, you have been asked to investigate the following:
Research Question: Is there evidence that children born with congenital heart disease who undergo reparative heart surgery during the first three months of life have a mean
MDI score different from 100, the mean for healthy infants?
Set up the null and alternative hypotheses to test the research question given in part b.
Again state them in words and using

notation. (3 pts)
H o
:
H a
: i.
Find the p-value to test the research question given in part h. (1 pt) p-value: _________________________
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j.
Write a conclusion in the context of the problem. (2 pts)
2.
a) Using the data the WSU STAT 110 student survey data ( Student Survey 3.JMP
) answer the following research question:
Is there evidence that WSU students spend more than 2 hours per day studying on average?
Show all your steps! (5 pts.) b) Also provide and interpret a 90% confidence interval for the mean number of minutes spent studying per day by WSU students.
(3 pts.)
3.
It is generally recommend that individuals exercise at least 3 times per week. Using the
STAT 110 student survey data ( Student Survey 3.JMP
) conduct a test to determine if the mean number of times worked out per week is more than 3 time per week for the population of WSU females and WSU males. To do this in JMP select Distribution and put Gender in the By box and Exercise Per Week in the Y, Columns box. a) Complete the table below (2 pts.)
Gender Mean
Exercise Statistics
Standard Deviation
Female
Male b) Conduct an appropriate test to determine if the mean number of times WSU female students exercise per week is greater than 3. State your conclusions. (4 pts.) c) Conduct an appropriate test to determine if the mean number of times WSU male students exercise per week is greater than 3. State your conclusions. (4 pts.) d) Examine and interpret the confidence intervals for the mean number of times exercised per week for both genders. What do you conclude on the basis intervals about the mean number of times exercised per week for WSU males vs. WSU females? (5 pts.)
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4.
Consumer Reports tested 14 brands of vanilla yogurt and found the following numbers of calories per serving:
160 200 220 230 120 180 140
130 170 190 80 120 100 170
A diet guide claims that you will get 120 calories from a serving of vanilla yogurt. Do these data provide evidence the diet guide’s claim is false? Use the appropriate test to answer this question. (4 pts) Hint: Be sure to check the normality assumption!
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