In a sample of 8 high school students, they spent an average of 28.8 hours each week doing sports with a sample standard deviation of 3.2 hours. find the 95% confidence interval, assuming the times are normally distributed.

Step-by-step explanation:

Since the population standard deviation is unknown, and the sample standard deviation , must replace it, the distribution  must be used for the confidence interval.

The sample size is n=8.

The degree of freedom is , .

With 95% confidence level, the (significance level) is 5%.

Hence with 7 degrees of freedom, . (Read from the t-distribution table see attachment)

The 95% confidence interval can be found by using the formula:

.

The sample mean is hours.

The sample sample standard deviation is hours.

We now substitute all these values into the formula to obtain:

.

We are 95% confident that the population mean is between 26.12 and 31.48  hours.

use formula for the circle a=3.14

step-by-step explanation:

4 candies

step-by-step explanation:

7 x 28 = 196

200 - 196 = 4 candies remaining.