DSST Statistics 5

Question 1

In a simple linear regression equation ŷ = 3 + 2x, if x increases by 1, ŷ:

Accepted Answer

Increases by 2

Answer

The slope coefficient (2) indicates the change in ŷ for each one-unit increase in x.

Question 2

The Central Limit Theorem states that the sampling distribution of the sample mean approaches normality as:

Accepted Answer

Sample size increases

Answer

As n increases (generally n ≥ 30), the distribution of sample means approximates a normal distribution regardless of the population shape.

Question 3

Which statistic is used to measure the spread of data around the regression line?

Accepted Answer

Standard error of the estimate

Answer

The standard error of the estimate (Sₑ) measures the average distance of observed values from the regression line.

Question 4

When two events are mutually exclusive, P(A or B) equals:

Accepted Answer

P(A) + P(B)

Answer

Mutually exclusive events cannot occur together, so P(A and B) = 0 and P(A or B) = P(A) + P(B).

Question 5

A researcher increases the alpha level from 0.01 to 0.05. This change:

Accepted Answer

Increases the probability of a Type I error

Answer

Alpha is the Type I error rate; raising it from 0.01 to 0.05 increases the chance of incorrectly rejecting a true null.

DSST - DANTES Subject Standardized Tests Practice Test