BSE Engineering Statistics and Data-Driven Decision Making

Question 1

A manufacturing process produces components with a mean diameter of 50 mm and a standard deviation of 0.5 mm.
What percentage of parts fall within ±2 standard deviations of the mean under a normal distribution?

Accepted Answer

95.45%

Answer

68.27%

Answer

99.73%

Answer

90.00%

Question 2

In hypothesis testing, a Type II error occurs when:

Accepted Answer

A false null hypothesis is not rejected

Answer

A true null hypothesis is rejected

Answer

The significance level is set too low

Answer

The sample size is too large

Question 3

Which control chart is most appropriate for monitoring the proportion of defective items in a production batch?

Accepted Answer

p-chart

Answer

X-bar chart

Answer

R chart

Answer

c-chart

Question 4

An engineering manager wants to determine the relationship between machine age (years) and maintenance cost ($). Which statistical method is most appropriate?

Accepted Answer

Simple linear regression

Answer

Chi-square test

Answer

ANOVA

Answer

Binomial distribution

Question 5

The coefficient of variation (CV) is defined as:

Accepted Answer

Standard deviation divided by mean, expressed as a percentage

Answer

Mean divided by standard deviation

Answer

Variance divided by sample size

Answer

Range divided by mean

Question 6

In a factorial experiment with 3 factors each at 2 levels, how many treatment combinations are required for a full factorial design?

Accepted Answer

8

Answer

6

Answer

9

Answer

12

Question 7

Which probability distribution is most commonly used to model the time between failures of a system assuming a constant failure rate?

Accepted Answer

Exponential distribution

Answer

Normal distribution

Answer

Binomial distribution

Answer

Poisson distribution