A sample of n -4 scores is selected from a population with u- 50 and o - 12. If the sample mean is M- 56, what is the z-score for this sample mean? O 4.00 O 2.00 O 1.00 O 0.50

One sample has n=7 and SS=35 and a second sample has n =17 and SS =45. What is the pooled variance for these two samples?

You are interested in comparing sleep habits of elementary school children.  Suppose you have agroup of eighth graders. You asked them in July to estimate about how many hours of sleep they get pernight, on average. You asked those same individuals the same question again in November, during theschool year. Which is the most appropriate test to use?

Two computer users were discussing tablet computers. A higher proportion of people ages 16 to 29 use tablets than the proportion of people age 30 and older. The table below details the number of tablet owners for each age group. Test at the 1% level of significance. (For subscripts let 1 = 16-29 year old users, and 2 = 30 years old and older users.)   16–29 year olds 30 years old and older Own a Tablet 69 231 Sample Size 625 2,313 NOTE: If you are using a Student's t-distribution for the problem, including for paired data, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.) Part (a) State the null hypothesis. H0: p1 < p2 H0: p1 > p2      H0: p1 ≠ p2 H0: p1 = p2 H0: p1 ≥ p2 Part (b) State the alternative hypothesis. Ha: p1 < p2 Ha: p1 ≠ p2      Ha: p1 = p2 Ha: p1 > p2 Ha: p1 ≤ p2 Part (c) In words, state what your random variable  P'1 − P'2  represents. P'1 −…