STATISTICAL TECHNIQUES AND TOOLS
CONFIDENCE INTERVALS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
Compute a 98% confidence interval:Last year, the times for Midlo soccer games were normally distributed with a standard deviation of 2.8 minutes. A random sample of 7 soccer games this year had an average length of 94 minutes.
|
|
(91.235, 96.765)
|
|
|
(91.827, 96.173)
|
|
|
(91.538, 96.462)
|
|
|
(90.674, 97.326)
|
Explanation:
Detailed explanation-1: -With a 95 percent confidence interval, you have a 5 percent chance of being wrong. With a 90 percent confidence interval, you have a 10 percent chance of being wrong. A 99 percent confidence interval would be wider than a 95 percent confidence interval (for example, plus or minus 4.5 percent instead of 3.5 percent).
Detailed explanation-2: -You must use the t-distribution table when working problems when the population standard deviation () is not known and the sample size is small (n<30). General Correct Rule: If is not known, then using t-distribution is correct. If is known, then using the normal distribution is correct.
There is 1 question to complete.