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.

go and ask your mom to you

the most boring ever written

step-by-step explanation:

i am writing something. yes, i plan to make it the most boring thing ever written. i go to the store. a car is parked. many cars are parked or moving. some are blue. some are tan. they have windows. in the store, there are items for sale. these include such things as soap, detergent, magazines, and lettuce. you can enhance your life with these products. soap can be used for bathing, be it in a bathtub or in a shower. apply the soap to your body and rinse. detergent is used to wash clothes. place your dirty clothes into a washing machine and add some detergent as directed on the box. select the appropriate settings on your washing machine and you should be ready to begin. magazines are stapled reading material made with glossy paper, and they cover a wide variety of topics, ranging from news and politics to business and stock market information. some magazines are concerned with more recreational topics, like sports card collecting or different kinds of hairstyles. lettuce is a vegetable.