10.1

9.

Right-sided; Population Mean

10.

Left-sided; Population Proportion

11.

Two-sided; Population Standard Deviation/Variance

12.

Right-sided; Population Proportion

13.

Left-sided; Population Mean

14.

Two-sided; Population Standard Deviation/Variance

15.

Ho: P = 0.105

H1: P > 0.105

Type I: We claim that the percentage has increased, but in reality it has not.

Type II: We claim that the percentage has not increased, but in reality it has increased.

17.

Ho: µ = 218,600

H1: µ < 218,600

Type I: We claim that the mean price has decreased, but in reality it has not.

Type II: We claim that the mean price has not changed, but in reality it has decreased.

19.

Ho: σ = 0.7

H1: σ < 0.7

Type I: We claim that the pressure variability has decreased, but in reality it has not.

Type II: We claim that the pressure variability has not changed, but in reality it has.

21.

Ho: µ = 47.47

H1: µ ≠ 47.47

Type I: We claim that the mean phone bill has changed, but in reality it has not.

Type II: We claim that the mean phone bill has not changed, but in reality it has.

10.2

7.

  1. z = 2.31
  2. P-value = 0.0104
  3. Reject the null hypothesis

9.

  1. z = -0.74
  2. P-value = 0.2296
  3. Do not reject the null hypothesis

11.

  1. z = -1.49
  2. P-value = 0.1362
  3. Do not reject the null hypothesis

13.

The probability of companies being winners is about 27%, which is relatively high. There is not sufficient evidence to prove that a majority of companies will be winners.

15.

  1. P-value = 0.2578

  2. There is not sufficient evidence to support the claim that more than 1.9% of Lipitor users experience flulike symptoms as a side effect. ⇒ Do not reject null hypothesis

17.

  1. P-value = 0.1492

  2. There is not sufficient evidence to support the claim that a majority of adults believe they will not have enough money in retirement. ⇒ Do not reject null hypothesis

19.

  1. P-value = 0.0040

  2. There is sufficient evidence to support the claim that the percentage of employed adults who feel basic mathematical skills are critical to their job has increased. ⇒ Reject the null hypothesis

10.3

1.

  1. 𝓉 = 2.602

  2. 𝓉 = 1.729

  3. 𝓉 = 2.160

2.

  1. 𝓉 = 1.321

  2. 𝓉 = 2.426

  3. 𝓉 = 2.449

3.

  1. 𝓉 = -1.379

  2. 𝓉 = -1.714

  3. The test statistic does not fall into the Rejection Region; the researcher does not have sufficient evidence against the null hypothesis. ⇒ Do not reject null hypothesis

4.

  1. 𝓉 = 2.674

  2. 𝓉 = 1.318

  3. The test statistic falls in the Rejection Region; the researcher has sufficient evidence against the null hypothesis. ⇒ Reject the null hypothesis

5.

  1. 𝓉 = 2.502

  2. 𝓉 = ±2.819

  3. The test statistic does not fall into the Rejection Region; the researcher does not have sufficient evidence against the null hypothesis. ⇒ Do not reject null hypothesis

11.

  1. Ho: µ = 67
    Ha: µ > 67

  2. P-value = 0.02 is the probability that the null hypothesis is true.

  3. (P-value = 0.02) < (α = 0.05) ⇒ Reject the null hypothesis

13.

  1. Ho: µ = 22
    Ha: µ > 22

  2. 200 ≥ 30 ✓

  3. 𝓉 = 2.176

  4. (0.01 < P-value < 0.02) < (α = 0.05) ⇒ Reject the null hypothesis

15.

𝓉 = -4.553

The test statistic falls in the Rejection Region; there is sufficient evidence to support the claim that alcoholic adolescents have hippocampal regions of less-than-normal volumes. ⇒ Reject the null hypothesis

17.

𝓉 = 0.8134

The test statistic does not fall into the Rejection Region; there is not sufficient evidence to support the claim that high-income individuals have higher credit scores. ⇒ Do not reject null hypothesis

19.

CI = (35.44, 42.36)

The test statistic is within the 95% Confidence Interval; there is not sufficient evidence to support the claim that the mean age of an inmate on death row has changed since 2002. ⇒ Do not reject null hypothesis

10.4

1.

  1. Χ² = 28.869

  2. Χ² = 14.401

  3. Χ²(lower) = 16.047
    Χ²(upper) = 45.772

3.

  1. Χ² = 20.496

  2. Χ² = 13.091

  3. The test statistic does not fall into the Rejection Region; the researcher does not have sufficient evidence against the null hypothesis. ⇒ Do not reject null hypothesis

x <- sd(c(108.5,80.4,67.4,95.5,58.0,86.3,75.9,70.9,65.1,72.0))
x
## [1] 15.20504

13.

Note. The sample standard deviation of the data shown is.\(15.205043\). You will have to knit this to see the number though.

Χ² = 6.426

The test statistic does not fall into the Rejection Region; there is not sufficient evidence to support the claim that the standard deviation of wait-time is less than 18.0s. ⇒ Do not reject null hypothesis

15.

Χ² = 15.639

The test statistic falls in the Rejection Region; there is not sufficient evidence to support the claim that Derrick Rose is more consistent than other shooting guards in the NBA. ⇒ Reject the null hypothesis