Exhibit 16-4 In a Laboratory Experiment, Data Were Gathered on the Life

question 80

Multiple Choice

Exhibit 16-4
In a laboratory experiment, data were gathered on the life span (y in months) of 33 rats, units of daily protein intake (x₁) , and whether or not agent x₂ (a proposed life extending agent) was added to the rats diet (x₂ = 0 if agent x₂ was not added, and x₂ = 1 if agent was added.) From the results of the experiment, the following regression model was developed. = 36 + 0.8x₁ - 1.7x₂
Also provided are SSR = 60 and SST = 180.
-Refer to Exhibit 16-4. The life expectancy of a rat that was not given any protein and that did not take agent x₂ is

• A)36.7
• B)34.3
• C)36
• D)38.4

---

Definitions:

Equal Variances

Assuming that two or more populations have the same variance, often an assumption in statistical tests comparing populations.

Sample Variances

Sample variances refer to the measurement of the variance within a sample from a population, providing an estimate of the population variance.

Population Variance

A measure that indicates the spread of a population's data points or how much the population's data values differ from the mean of the population.

Significance Level

The probability of rejecting the null hypothesis when it is true, often denoted by alpha, and used as a threshold to interpret the p-value in hypothesis testing.