Question 1

A company records the color of cars sold (red, blue, black, white) and the price at which each car is sold. Which of the following correctly classifies these variables?

Accepted Answer

Color is a cualitativa variable; price is a cuantitativa variable.

Question 2

Which of the following best describes a variable measured on an ordinal scale?

Accepted Answer

The variable represents categories with a meaningful order but not necessarily equal intervals.

Question 3

A survey asks respondents to rate their satisfaction from 1 (very dissatisfied) to 5 (very satisfied). What type of variable is this?

Accepted Answer

Cualitativa ordinal

Question 4

Given the following frequency distribution for the number of books read by students in a month: 0 books (5 students), 1 book (8 students), 2 books (12 students), 3 books (10 students). What is the cumulative frequency for '2 books'?

Accepted Answer

$$25$$

Question 5

If a dataset has a mean of $$50$$, a median of $$45$$, and a mode of $$40$$, what can you infer about the shape of the distribution?

Accepted Answer

The distribution is right-skewed.

Question 6

Which of the following is the correct formula for the sample variance $$s^2 of a $$dataset with $$n$$ observations $$x_1$$, $$x_2$$, ..., x_n$$ and sample mean $$\bar{x}$$?

Accepted Answer

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

Question 7

Which graphical method is most appropriate for displaying the distribution of a single quantitative variable?

Accepted Answer

Boxplot

Question 8

A boxplot shows a long whisker on the right side. What does this indicate about the data?

Accepted Answer

The data is right-skewed.

Question 9

In a contingency table of gender (male/female) and preference for a new product (like/dislike), which of the following best describes a conditional percentage?

Accepted Answer

The percentage of males who like the product.

Question 10

Which of the following statements about the correlation coefficient $$r is $$correct?

Accepted Answer

$$r$$ measures the strength and direction of a linear relationship between two variables.

Question 11

Suppose the $$R^2$$ value for a linear regression model is $$0.81. $$What does this mean?

Accepted Answer

81% of the variation in the dependent variable is explained by the model.

Question 12

A researcher wants to analyze the relationship between education level (high school, college, graduate) and employment status (employed, unemployed). Which statistical tool should they use?

Accepted Answer

Contingency table

Question 13

Which of the following is NOT a measure of central tendency?

Accepted Answer

Standard deviation

Question 14

A scatterplot of two variables shows points tightly clustered around a straight line with a positive slope. What can you conclude?

Accepted Answer

There is a strong positive linear relationship.

Question 15

Which of the following formulas represents the linear regression equation for predicting $$y$$ from $$x$$?

Accepted Answer

$$y = a + bx$$

Question 16

If the absolute frequency of a category is 20 and the total number of observations is 100, what is the relative frequency?

Accepted Answer

$$0.2$$

Question 17

Which of the following best describes the purpose of a stem-and-leaf plot?

Accepted Answer

To display the distribution of a quantitative variable while preserving the original data values.

Question 18

A dataset has a standard deviation of $$0. $$What does this indicate?

Accepted Answer

All values are equal.

Question 19

Which of the following is a correct interpretation of a negative correlation between two variables?

Accepted Answer

As one variable increases, the other tends to decrease.

Question 20

In a business context, which of the following is an example of a quantitative continuous variable?

Accepted Answer

The annual revenue in dollars

Resumen de Estadística para Negocios: Conceptos Fundamentales

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드