BSE Engineering Statistics and Data-Driven Decision Making 3

Question 1

A manager must choose between two suppliers based on lead time data.
Supplier A has a mean of 5 days (σ=0.5), Supplier B has a mean of 5 days (σ=2).
Which statistical measure best differentiates them?

Accepted Answer

Standard deviation

Answer

Mean

Answer

Median

Answer

Mode

Question 2

In Design of Experiments (DOE), a 'blocking' factor is used to:

Accepted Answer

Reduce variability by grouping experimental units with similar characteristics

Answer

Prevent certain treatments from being tested

Answer

Increase the number of replicates required

Answer

Eliminate the need for randomization

Question 3

The Central Limit Theorem (CLT) states that as sample size increases, the sampling distribution of the sample mean:

Accepted Answer

Approaches a normal distribution regardless of population shape

Answer

Approaches the same shape as the population distribution

Answer

Has a variance equal to the population variance

Answer

Becomes identical to a t-distribution

Question 4

Which regression diagnostic is used to detect heteroscedasticity (non-constant variance) in residuals?

Accepted Answer

Residuals vs. fitted values plot

Answer

Normal probability plot of residuals

Answer

Durbin-Watson test

Answer

Variance inflation factor (VIF)

Question 5

An engineering team runs an ANOVA and obtains a significant F-statistic. What does this tell the team?

Accepted Answer

At least one group mean differs significantly from the others

Answer

All group means are significantly different from each other

Answer

The variances of all groups are equal

Answer

The data follow a normal distribution

Question 6

In the context of acceptance sampling, an Operating Characteristic (OC) curve shows:

Accepted Answer

The probability of lot acceptance as a function of the actual lot defect proportion

Answer

The relationship between defect rate and production cost

Answer

The sample size required for a given confidence level

Answer

The cumulative defect count over time

Question 7

A Pearson correlation coefficient of r = -0.92 between two engineering variables indicates:

Accepted Answer

A strong negative linear relationship

Answer

A weak negative linear relationship

Answer

A strong positive linear relationship

Answer

No meaningful linear relationship