Homework Chapter 8

Section 2

Q30

$$7.2\pm 1.96\ast \frac{5.6}{\sqrt{200}}$$

Q32

1. The population is the cost of rooms from the three hotel chains.

2. $150\pm 1.96\frac{17.2}{sqrt50}$

3. $165\pm 1.96\frac{22.5}{sqrt50}$

4. $125\pm 1.96\frac{12.8}{sqrt50}$

5. (see figure 8.5)

Section 3

Q18

[1] 3.92

Q19

[1] 2.771859

Q20

[1] 1.96

Q31

1. 53.2614658, 54.7385342
2. 71.277054, 72.722946

Q37

1. 0.4832625, 0.6767375
2. It supports the claim because 67% is within the boundary of interval

Section 4

Q14

Point: 7.9

SE: 0.59

Margin: 1.15

CI: [6.75, 9.05]

Q19

Point: 74

SE: 25.47

Margin: 49.92

CI: [24.08, 123.92]

Section 5

Q13

Point: -0.04

SE: 0.09

Margin: 0.18

CI: [-0.22, 0.15]

Q23

Point estimate:

[1] 0.56

Margin:

[1] 0.15

Point: 0.25

SE: 0.11

Margin: 0.22

CI: [0.03, 0.47]

Section 7

Q1

243 ### Q9

$n_1=n_2=2153$

Q15

$n_1=n_2=70$