10.1

9.

right tailed.

10.

left tailed.

11.

two-tailed.

12.

right tailed.

13.

left tailed.

14.

two-tailed.

15.

Ho: p=0.399

H1: p>0.399

  1. Type 1 error would be to conclude that the proportion of students who earn a bachelor’s degree within six years is greater than 0.399, when in fact it is equal to 0.399.

  2. Type II error would be to conclude that the proportion of students who earn a bachelor’s degree within six years isn’t greater than 0.399 when in fact it is.

17.

Ho: μ=$245,700

H1: μ<$245,700

  1. Type I error would be to conclude that the mean price of an existing single-family home is smaller than $245,700, when in fact it is $245,700.

  2. Type II error would be to conclude that the mean price of an existing single-family home is not smaller than $245,700, when in fact it is.

19.

Ho: σ=0.7 psi

H1: σ<0.7 psi

  1. The quality control manager would be committing a type I error by rejecting that the pressure variability is not 0.7 psi when in fact it is.

  2. The quality control manager would be committing a type II error by not rejecting a pressur variability equal to 0.7 psi, when in fact it is smaller.

21.

Ho: μ=$48,79

H1: μ≠$48,79

  1. Type I error would be concluding that the mean monthly cell phone bill is different than $48,79, when in fact it is $48,79.

  2. Type II error would be concluding that the mean monthly cell phone bill is $48,79, when in fact it is different than $48,79.