Question 1

Which of the following best describes the difference between descriptive and inferential statistics in business decision-making?

Accepted Answer

Descriptive statistics summarize and organize data, while inferential statistics use sample data to make generalizations about a population.

Question 2

A company wants to estimate the average amount spent by customers in its stores. They randomly select 100 receipts from last month and calculate the mean. Which statistical concept is being applied?

Accepted Answer

Sample statistic

Question 3

Which formula correctly calculates the sample mean $$\bar{x}$$ for a dataset with $$n$$ observations $$x_1$$, $$x_2$$, ..., x_n$$?

Accepted Answer

$$\bar{x} = \frac{\sum_{i=1}^{n} x_i}{n}$$

Question 4

A business analyst is comparing the effectiveness of two marketing campaigns using the following data: Campaign A had a mean sales increase of $$10,000$$ with a standard deviation of $$2,000$$, and Campaign B had a mean sales increase of $$8,000$$ with a standard deviation of $$1,000. $$Which campaign showed more consistent results?

Accepted Answer

Campaign B, because it had a lower standard deviation.

Question 5

Which of the following is the correct formula for the sample variance $$s^2$$?

Accepted Answer

$$s^2$$ = \frac{\sum_{i=1}^{n} (x_i - \bar{x}$$)^2$$}{n-1}$$

Question 6

A retail manager wants to know if the average transaction value differs between weekdays and weekends. Which statistical test is most appropriate for this scenario?

Accepted Answer

Two-sample t-test

Question 7

If a dataset is highly skewed to the right, which measure of central tendency is most likely to be greater than the others?

Accepted Answer

Mean

Question 8

A business wants to predict future sales based on advertising spend. Which statistical method should they use?

Accepted Answer

Simple linear regression

Question 9

Which of the following is NOT a type of data sampling technique discussed in business statistics?

Accepted Answer

Exponential sampling

Question 10

A company collects data on customer satisfaction scores (1-5 scale) from all its stores. Which type of data is this?

Accepted Answer

Ordinal

Question 11

Which formula represents the calculation of a z-score for a value $$x in a $$dataset with mean $$\mu$$ and standard deviation $$\sigma$$?

Accepted Answer

$$z = \frac{x - \mu}{\sigma}$$

Question 12

A business analyst wants to test if the proportion of customers who prefer online shopping is different from 50%. Which statistical test should be used?

Accepted Answer

One-sample proportion z-test

Question 13

Which of the following statements about p-values in hypothesis testing is correct?

Accepted Answer

A p-value less than the significance level indicates strong evidence against the null hypothesis.

Question 14

A company wants to compare the mean sales of three different stores. Which statistical method should be used?

Accepted Answer

ANOVA (Analysis of Variance)

Question 15

Which formula is used to calculate the correlation coefficient $$r$$ between two variables $$x$$ and $$y$$?

Accepted Answer

$$r = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sqrt{\sum (x_i - \bar{x})^2$ \sum (y_i - \bar{y})^2$}}$$

Question 16

A business wants to know if there is a relationship between region (North, South, East, West) and product preference (A, B, C). Which statistical test is most appropriate?

Accepted Answer

Chi-square test for independence

Question 17

Which of the following is a correct interpretation of a 95% confidence interval for the mean sales of a product?

Accepted Answer

If we repeated the sampling many times, about 95% of the intervals would contain the true mean.

Question 18

A manager wants to know if the average time to serve a customer has decreased after a new training program. Which hypothesis test should be used?

Accepted Answer

Paired-sample t-test

Question 19

Which formula is used to calculate the standard error of the mean $$SE$$ for a sample with standard deviation $$s$$ and sample size $$n$$?

Accepted Answer

$$SE = \frac{s}{\sqrt{n}}$$

Question 20

A business analyst finds a correlation coefficient of $$r = 0.85$$ between advertising spend and sales. What does this indicate?

Accepted Answer

There is a strong positive linear relationship between advertising spend and sales.

BUSI 1030: Data Analysis and Interpretation – Syllabus Overview and Topic Guide

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