Question

John measured the total playing time of 30 randomly chosen CDs from his very large collection and found a mean of 77.9 minutes and a standard deviation of 11.6 minutes. Give the 93% confidence interval for the population mean, assuming that the population is approximately normally distributed. Round the endpoints to two decimal places.

Confidence interval: ( , )

Studies have suggusted that twins, in their early years, tend to have lower IQs and pick up language more slowly than non-twins. The slower intellectual growth may be caused by benign parental neglect. Suppose it is desired to estimate the mean attention time given to twins per week by their parents. A sample of 34 sets of two-year-old twin boys was taken, and after one week the attention time received was recorded. The mean was found to be 32.9 hours with a standard deviation of 14.3 hours. Use this information to contruct a 98% confidence interval for the mean attention time given to all twin boys by their parents, assuming that the population is approximately normally distributed. Round the endpoints to one decimal place.

Confidence interval: ( , )

Answer #1

John measured the total playing time of 30 randomly chosen CDs
from his very large collection and found a mean of 77.9 minutes and
a standard deviation of 11.6 minutes. Give the 93% confidence
interval for the population mean, assuming that the population is
approximately normally distributed. Round the endpoints to two
decimal places.
Confidence interval:
tudies have suggusted that twins, in their early years, tend to
have lower IQs and pick up language more slowly than non-twins. The
slower...

A survey of 20 randomly selected adult men showed that the mean
time they spend per week watching sports on television is 9.34
hours with a standard deviation of 1.34 hours.
Assuming that the time spent per week watching sports on
television by all adult men is (approximately) normally
distributed, construct a 90 % confidence interval for the
population mean, μ .
Round your answers to two decimal places.
Lower bound: Enter your answer; confidence interval, lower
bound
Upper bound:...

At a large company, the Director of Research found that the
average work time lost by employees due to accidents was 94 hours
per year. She used a random sample of 20 employees. The standard
deviation of the sample was 5.9 hours. Estimate the population mean
for the number of hours lost due to accidents for the company,
using a 95% confidence interval. Assume the variable is normally
distributed. Round intermediate answers to at least three decimal
places. Round your...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 5 minutes ago

asked 5 minutes ago

asked 20 minutes ago

asked 41 minutes ago

asked 49 minutes ago

asked 57 minutes ago

asked 57 minutes ago

asked 58 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago