Chapter 10.1 9-14, 15-21 odds

Right tailed, mu.

Left tailed, p.

Double-tailed, o.

Right tailed, p.

Left tailed, mu.

Double-tailed, o.

HO: p = .105

HA: p > .105

Type I error: Determining the true proportion p of births to teenage mothers is greater then .105 when it is not.

Type II error: Determining the true proportion p of births to teenage mothers is not greater then .105 when it is.

HO: mu = $218,600

HA: mu < $218,600

Type I error: Determining the true mean price mu of an existing family home is less than $218,600 when it is not.

Type II error: Determining the true mean price mu of an existing family home is not less than $218,600 when it is.

HO: o = 0.7 psi

HA: o < 0.7 psi

Type I error: Determining the true standard deviation o in the pressure required to open a certain valve is less than 0.7 psi when it is not.

Type II error: Determining the true standard deviation o in the pressure required to open a certain valve is not less than 0.7 psi when it is.

HO: mu = $47.47

HA: mu ≠ $47.47

Type I error: Determining the true mean monthly cell phone bill is different from $47.47 when it isn’t.

Type II error: Determining the true mean monthly cell phone bill is not different from $47.47 when it is.

Chapter 10.2 7-19 odds (only need to do the pvalue approach)

np(1-p) = 200(.3)(1-.3) = 42 is greater than or equal to 10.

P-value = 0.0104

Reject the Null Hypothesis.

np(1-p) = 150(.55)(1-.55) = 37.13 is greater than or equal to 10.

P-value = 0.2296

Do not reject the Null Hypothesis.

np(1-p) = 500(.9)(1-.9) = 45 is greater than or equal to 10.

P-value = 0.1362

Do not reject the Null Hypothesis.

About 27 out of 100 samples have a proportion greater than or equal to 0.5 than the one obtained if the proportion is truly 0.5. Do not reject the Null Hypothesis because there is not sufficient evidence that p > 0.5.

P-value = 0.2578

Do not reject the Null Hypothesis, there is not sufficient evidence at the α = 0.01 level of significance that p > 0.019.

P-value = 0.1401

Do not reject the Null Hypothesis, there is not sufficient evidence at the α = 0.05 level of significance that p > 0.5 (the majority of adults in the US believe they don’t have enough money in retirement).

P-value = 0.0047

Reject the Null Hypothesis, there is sufficient evidence at the α = 0.05 level of significance that p > 0.56.