Question

Were learning about hypothesis testing procedures, but I cannot seem to get the same responses

question3.

An investigator hypothesizes that cholesterol levels in children might be affected by educating their parents on proper nutrition and exercise. A sample of 40 families with a child between the ages of 10-15 who has been diagnosed with high cholesterol agree to participate in the study. All parents are provided educational information on nutrition and exercise. After following the prescribed program, their child's total cholesterol level is measured. The children's mean cholesterol level is 175 with a standard deviation of 19.5. Is there a significant evidence of a reduction in total cholesterol in the children? Run the appropriate test at the 5% level of significance and assume that the null value for total cholesterol is 191.

What would be an appropriate calculation for Step 4 of Hypothesis Testing to answer this question?

Group of answer choices

A.(19.5-6.32)/(191/13.23)

B.(175-191)/(19.5/6.32)

C.(6.32-19.5)/(175/13.82)

D.(191-175)/(19.5/6.32)

QUESTION 4

The mean lifetime for cardiac stents is 8.9 years. A medical device company has implemented some improvements in the manufacturing process and hypothesizes that the lifetime is now longer. A study of 40 new devices reveals a mean lifetime of 9.7 years with a standard deviation of 3.4 years. Is there statistical evidence of a prolonged lifetime of the stents? Run the test at a 5% level of significance.

What would be an appropriate set up for Step 1 of Hypothesis Testing to answer this question?

  

Group of answer choices

a.H0: u=9.7; H1: u>9.7; alpha=0.05

b.H0: u=8.9; H1: u<8.9; alpha=0.05

c.H0: u=8.9; H1: u>8.9; alpha=0.05

d.H0: u=9.7; H1: u<9.7; alpha=0.05

QUESTION 5

Recent recommendations suggest 60 minutes of physical activity per day. A sample of 50 adults in a study of cardiovascular risk factors report exercising a mean of 38 minutes per day with a standard deviation of 19 minutes. Based on the sample data, is the physical activity significantly less than recommended? Run the appropriate test at a 5% level of significance.

What would be an appropriate set up for Step 3 of Hypothesis Testing to answer this question?

Group of answer choices

A. Decision Rule: Reject H0 if Z<=-1.96

B.Decision Rule: Reject H0 if Z<=-1.645

C.Decision Rule: Reject H0 if Z<=-1.96 or Z>=1.96

D.Decision Rule: Reject H0 if Z>=1.645

Answer 1