PSY 418
1.
Jane needs to score in the top 2.5% percent of an aptitude test to
qualify for a job. The mean of test is 75 and standard deviation is
10. How high of a score does she need to get?
2.
The standard deviation for the number of students attending a class is
5. Over five classes, 25, 35, 30, 26, and 20 students attend the
class. What is the mean number of students attending for these five
classes? What is the standard deviation associated with this mean?
3.
Mia needs to figure out the mean number of hours children spend
watching TV per week. She needs the standard deviation associated
with the mean to be less than or equal to 2. The standard deviation
for how many hours children watch TV is 6 hours per week. How many
children does she need to survey?
4.
Dave runs an experiment with 1241 subjects. Kate runs the same
experiment (on the same population) with 476 subjects. What is Kate's
standard deviation of the mean divided by Dave's standard deviation of
the mean?
5.
The weight of a seal has a standard deviation of 20 pounds.
An animal trainer at Sea World is interested in how heavy the seals are
at the park (on average). Eight seals at the park are weighed and
weigh 200, 220, 300, 175, 218, 315, 180, and 200 pounds.
What is the mean weight of the seals?
What is the confidence 95% confidence interval for the above mean?
What is the confidence 99% confidence interval for the above mean?