BSIE Probability & Statistics 5

Question 1

The power of a statistical test is defined as:

Accepted Answer

1 − β (one minus the Type II error probability)

Answer

Power = 1 − β, the probability of correctly rejecting a false null hypothesis.

Question 2

In a 2×2 contingency table, the chi-square test of independence assesses:

Accepted Answer

Whether two categorical variables are associated

Answer

The chi-square test of independence determines whether the distribution of one categorical variable differs across levels of another.

Question 3

A negative covariance between two random variables X and Y indicates:

Accepted Answer

When X is above its mean, Y tends to be below its mean

Answer

Negative covariance means that high values of X tend to be paired with low values of Y, indicating an inverse linear relationship.

Question 4

Which sampling method divides the population into subgroups and randomly samples from each subgroup proportionally?

Accepted Answer

Stratified sampling

Answer

Stratified sampling divides the population into strata (subgroups) and draws random samples from each, ensuring representation of all subgroups.

Question 5

The interquartile range (IQR) is calculated as:

Accepted Answer

Q3 − Q1

Answer

IQR = Q3 − Q1, representing the spread of the middle 50% of the data.

BSIE - Bachelor of Science in Industrial Engineering Practice Test