To use a t procedure, which of the following must be true?

i. the standard deviation of the parent population must be unknown.
ii. the sample size must be small (less than 30).
iii. the parent population must be normally distributed.

a) i only
b) i and iii only
c) iii only
d) ii and iii only
e) i, ii, iii

For the equations below which statement is true ? -2x=14 6x=-42

Last year, a state university received 3,560 applications from boys. of those applications, 35 percent were from boys who lived in other states. part a)how many applications did the university receive from boys who lived in other states? part b)applications to the university from boys represented 40percent of all applications. how many applications did the university receive in all? i don't how to do part b so me and plz tell how you got your answer

This stem-and-leaf plot represents the heights of the students on ralph's basketball team. one student's height is missing from the plot. if the mean height of all the students on the team is 61 inches, what is the missing height? a. 55 in. b. 59 in. c. 61 in. d. 65 in.