For each study, decide if the two samples are independent samples or paired samples. In a random sample of 100 students, the change in hours of sleep for each student during and after finals week were compared.
a. Independent samples
b. Paired samples
Q. 2The head circumference is measured for a sample of 17 girls and a separate sample of 12 boys. The mean for the girls was 49 cm with a standard deviation of 1.25 cm. The mean for the boys was 50 cm with a standard deviation of 0.95 cm. What is the value of the pooled standard error for the difference in mean head circumference between girls and boys?
a. 0.41
b. 1.29
c. 0.43
d. 1.14
Q. 3For each study, decide if the two samples are independent samples or paired samples. In a random sample of 100 students (60 women and 40 men), the average hours of sleep during finals week were compared.
a. Independent samples
b. Paired samples
Q. 4The amount of time single men and women spend on house work is measured for 15 single women and 25 single men. For the women the mean was 7 hours/week with a standard deviation of 1.5 . For the men the mean was 4.5 hours/week with a standard deviation of 1.1 . What is the value of the pooled standard deviation for the difference in mean time spent on housework between single men and women?
a. 1.30
b. 0.45
c. 1.59
d. 1.26
Q. 5For each study, decide if the two samples are independent samples or paired samples. A group of 50 students had their blood pressures measured before and after watching a movie containing violence. The mean blood pressure before the movie was compared with the mean pressure after the movie.
a. Independent samples
b. Paired samples
Q. 6The head circumference is measured for a sample of 15 girls and a separate sample of 15 boys. What is the correct combination of degrees of freedom and the value of the multiplier t for a 90 confidence interval for the difference in mean head circumference between girls and boys?
a. df = 13, t = 1.77
b. df = 28, t = 1.70
c. df = 28, t = 2.05
d. df = 30, t = 1.70
Q. 7For 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