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

question 57

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 given 2 units of agent x₂ daily, but was not given any protein is

• A)32.6
• B)36
• C)38
• D)34.3

---

Definitions:

Physical Barrier

Any natural or artificial structure that blocks or limits movement, spread, or access of organisms or materials.

Polyploidy

The condition of having more than two complete sets of chromosomes in an organism, common in plants and some animal species.

Sexual Dimorphism

The noticeable difference in appearance between males and females of the same species, beyond just the reproductive organs.

Male Traits

Characteristics, either physiological or behavioral, that are commonly seen in males of a species, often influenced by genetic and hormonal factors.