Question

In: Statistics and Probability

Researchers have collected data from a random sample of six students on the number of hours...

Researchers have collected data from a random sample of six students on the number of hours spent studying for an exam and the grade received on the exam as given in Table 6.5.

Table 6.5

Observation

Grade

Number of Hours Studying

1

85

8

2

73

10

3

95

13

4

77

5

5

68

2

6

95

12

d) Find and interpret a 90% confidence interval for the true population slope parameter.

Solutions

Expert Solution

In Excel

data -> data analysis -> regression

SUMMARY OUTPUT
Regression Statistics
Multiple R 0.821032015
R Square 0.67409357
Adjusted R Square 0.592616963
Standard Error 7.270814178
Observations 6
ANOVA
df SS MS F Significance F
Regression 1 437.3743781 437.3743781 8.273461441 0.045178178
Residual 4 211.4589552 52.86473881
Total 5 648.8333333
Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Lower 90.0% Upper 90.0%
Intercept 63.72761194 7.064410201 9.02093878 0.00083633 44.11366482 83.34155906 48.66737176 78.78785212
Number of Hours Studying 2.212686567 0.769265536 2.876362536 0.045178178 0.076863036 4.348510098 0.572730307 3.852642827

90% confidence interval is (0.5727,3.8526)


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