Bcom Bachelor of Commerce Business Statistics 2

Question 1

In a normal distribution, approximately what percentage of data falls within one standard deviation of the mean?

Accepted Answer

68%

Answer

The empirical rule states that about 68% of observations in a normal distribution fall within ±1 standard deviation of the mean.

Question 2

What is 'simple linear regression' used for?

Accepted Answer

Modeling the relationship between one independent variable and one dependent variable

Answer

Simple linear regression estimates how changes in one predictor variable (X) are associated with changes in an outcome variable (Y) using the equation Y = a + bX.

Question 3

What does a correlation coefficient of +1 indicate?

Accepted Answer

A perfect positive linear relationship between two variables

Answer

A correlation of +1 means the two variables move together in perfect lockstep—when one increases, the other increases by a proportional amount.

Question 4

What is a 'Type I error' in hypothesis testing?

Accepted Answer

Rejecting a true null hypothesis (false positive)

Answer

A Type I error (false positive) occurs when a researcher incorrectly rejects the null hypothesis when it is actually true.

Question 5

In a frequency distribution, the 'class interval' refers to:

Accepted Answer

The width or size of each group in the distribution

Answer

The class interval (or class width) is the range of values covered by each group in a frequency distribution, calculated as upper boundary minus lower boundary.

Bcom Bachelor of Commerce Practice Test

Bcom Bachelor of Commerce Practice Test

Bcom Bachelor of Commerce Business Statistics 2