Author Question: Scores on an achievement test had an average of 70 and a standard deviation of 10 . Serena's score ... (Read 73 times)

brutforce · **on:** Jul 24, 2018

Scores on an achievement test had an average of 70 and a standard deviation of 10 . Serena's score was 85 . Assuming the scores have approximately a normal distribution, about what proportion of students scored lower than Serena?
a. 0.93
b. 0.07
c. 0.84
d. 0.68

Question 2

For each study, decide if the two samples are independent samples or paired samples. A group of 100 students were randomly assigned to receive vitamin C (50 students) or a placebo (50 students). The groups were followed for 2 weeks and the proportions of students with colds were compared.
a. Independent samples
b. Paired samples