A student randomly selects 10 paperbacks at a store. The sample standard deviation is $1.50. Construct a 95% confidence interval for the population standard deviation, o. Assume the data are normally distributed. Don't write the dollar sign in your answers. Lower = Upper =

One hundred teachers attended a seminar on mathematical problem solving. The attitudes of twelve of the teachers were measured before and after the seminar. A positive number for change in attitude indicates that a teacher's attitude toward math became more positive. The 12 change scores are as follows: 3; 8; -1; 1; 0; 4; -3; 2; -1; 5; 4; -2 what is the standard deviation for this sample? what is the median change score? find the change score that is 2.2 standard deviations below the mean.

Nathan takes the State Aptitude Assessment, which has a mean of 350 and a standard deviation of 50. His brother Kyle takes the Regional Readiness Test, which has a mean of 300 and a standard deviation of 45. If Kyle's score was 375, what is the cooresponding z score? a. +2.22 b. +1.00 c. +1.67 d. -1.67

The ages in years of a random sample of shoppers at a gamming store are shown. 12, 17, 23, 13, 20, 16, 20, 18, 13, 18. Find the range, mean, variance and standard deviation.