college statistics
posted by melba on .
consider a population with a mena =51.6 and a sd=5.9 (A) calculate the z score for x= 50.5 from a sample of size 47. (b) could this z score be used in calculating probabilities using table 3 in appendix b in text book ahy or ahy not

It would help if you proofread your questions before you posted them.
Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score. Multiply by 47.
Is this your "table 3 in appendix b"? 
Twelve different video games showing substance use were observed and the duration times of game play ( in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. use the data to construct a 95% confidence interval estimate of mean duration of game play.
4061,3886,3865,4023,4309,4821,4645,4021,5024,4812,4331,4325