Author Question: About 90 of the general population is right-handed. A researcher speculates that artists are less ... (Read 89 times)

cherise1989 · **on:** Jul 24, 2018

About 90 of the general population is right-handed. A researcher speculates that artists are less likely to be right-handed than the general population. In a random sample of 100 artists, 83 are right-handed. Which of the following best describes the p-value for this situation?
a. The probability that the population proportion of artists who are right-handed is 0.90.
b. The probability that the population proportion of artists who are right-handed is 0.83.
c. The probability the sample proportion would be as small as 0.83, or even smaller, if the population proportion of artists who are right-handed is actually 0.90.
d. The probability that the population proportion of artists who are right-handed is less than 0.90, given that the sample proportion is 0.83.

Question 2

Grade school students, especially the ones in higher grades, tend to spend a lot of time on the computer already. The average amount of time 4th grade boys spend on the computer is 5 hours per week, with a standard deviation of 1 hour. For 5th grade boys the average increases to 7 hours per week with a standard deviation of 1.5 hours. Random sample of 20 4th grade students and 25 5th grade students are to be selected. What is the expected value for the difference in sample means (5th 4th grade)?