Randomly selected statistics students participated in an experiment to test their ability to determine when 1 min (or 60 seconds
) had passed. Forty students yielded a sample mean of 58.3 sec. Assume that the population standard deviation is 9.5 seconds and that there is a 95% confidence interval estimate of the population mean of all students. 55.4 sec < μ < 61.2 sec Give a correct interpretation of the confidence interval. A. We are 95% confident that the interval from 55.4 seconds to 61.2 seconds actually does contain the true value of μ.
B. 95% of sample means fall between 55.4 seconds and 61.2 seconds.
C. There is a 95% chance that the true value of μ will fall between 55.4 seconds and 61.2 seconds.
D. We are confident that 95% of values between 55.4 seconds and 61.2 seconds represent the true value of the population mean.
A. We are 95% confident that the interval from 55.4 seconds to 61.2 seconds actually does contain the true value of μ.
Explanation:
In statistics, confidence interval is the interval estimate about the population parameter of interest at certain level of confidence like 95%. A 95% confidence interval gives us a range of values that we can be 95% confident contains the true mean of the population.
