In a simple linear regression model based on over 100 observations, you are given the following estimates.

1. The estimated slope is –1.03.
2. The standard error of the estimated slope is 0.06.

Calculate the 95% confidence interval for the slope.

• (–1.15, –0.91)
• (–1.13, –0.93)
• (–1.11, –0.95)
• (–1.09, –0.97)
• (–1.07, –0.99)

Copyright 2023. The Society of Actuaries, Schaumburg, Illinois. Reproduced with permission.

Key: A

Using the rule of thumb t-value of 2 produces an interval of –1.03 ± 2(0.06) for an interval of (–1.15, –0.91). Note that if the more precise value of 1.96 is used, the same answer (to two decimal places) is obtained.