9 1 11 pts in the population new yorkers have an

9. 1. (11 pts) In the population, New Yorkers have an average of 2 pets in their homes,
with a standard deviation of 1. I am interested in evaluating whether or not

medical doctors differ from the population in regard to number of pets owned.
Below is data from 9 doctors. Test this hypothesis using an alpha level of .01.
# of pets
0
1
0
0
1
3
2
1
1
a. (2 pts) What is the appropriate test? z Test
b. (1 pt) State the null hypothesis: Medical doctors do not have less pets
than the population.
c. (1 pt) State the alternative hypothesis: Medical doctors have less pets than
the population..
d. (2 pts)Find the critical value: -2.33
e. (2 pts)Calculate the obtained statistic: -3.003
f. (2 pts)Make a decision: Reject the null
g. (1 pt) What does your decision mean? Medical doctors do have less pets
than the population.
10. 2. (11 pts) A doctor believes that the babies of smokers have lower birth weights
than the average baby. It is well-known that the average newborn weights 7.4lbs,
with a standard deviation of 1lb. The doctor collects data from 15 self-reported
smokers who recently gave birth at a local hospital. He calculates their mean
baby birth weight to be 6.2lbs. Test the hypothesis that babies of smokers have
lower birth weights than the average newborn using an alpha level of .05.
a. (2 pts) What is the appropriate test? Z Test
b. (1 pt) State the null hypothesis: Babies of smokers do not have lower
birth weights than the average baby.
c. (1 pt) State the alternative hypothesis: Babies of smokers have lower
birth weights than the average baby.
d. (2 pts) Find the critical value: -1.65
e. (1 pt) Calculate the obtained statistic: -4. 62
f. (2 pts) Make a decision: Reject the null.
g. (1 pts) What does your decision mean? That babies of smokers do have
lower birth weights than average babies.