In: Statistics and Probability
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.
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)