Expert I Statistics (11, only in math 20-2 not math 20-1)

Question 1

What is the definition of mean in statistics?

Answer 1

The mean is the average of a set of numbers calculated by adding them together and dividing by the number of values.

Question 2

True or False: The median is the middle value in a set of numbers when arranged in numerical order.

Answer 2

True

Question 3

What is the range of a data set?

Answer 3

The range is the difference between the largest and smallest values in a data set.

Question 4

What is the formula for calculating standard deviation?

Answer 4

The standard deviation is calculated by taking the square root of the variance.

Question 5

What does the term ‘outlier’ refer to in statistics?

Answer 5

An outlier is a data point that differs significantly from other observations in a data set.

Question 6

What is the mode of a data set?

Answer 6

The mode is the value that appears most frequently in a data set.

Question 7

What is the formula for calculating variance?

Answer 7

Variance is calculated by taking the average of the squared differences from the mean.

Question 8

What is the purpose of hypothesis testing in statistics?

Answer 8

Hypothesis testing is used to determine if there is enough evidence to reject a null hypothesis.

Question 9

What is the difference between a population and a sample in statistics?

Answer 9

A population includes all members of a specified group, while a sample is a subset of the population used for analysis.

Question 10

What is the central limit theorem?

Answer 10

The central limit theorem states that the distribution of sample means approaches a normal distribution as the sample size increases.

Question 11

What is the purpose of a confidence interval in statistics?

Answer 11

A confidence interval is used to estimate the range within which the true population parameter is likely to fall.

Question 12

What is the difference between correlation and causation?

Answer 12

Correlation indicates a relationship between two variables, while causation implies that one variable directly influences the other.

Question 13

What is a p-value in hypothesis testing?

Answer 13

A p-value is the probability of obtaining results as extreme as the observed data, assuming the null hypothesis is true.

Question 14

What is a Type I error in hypothesis testing?

Answer 14

A Type I error occurs when the null hypothesis is rejected when it is actually true.

Question 15

What is a Type II error in hypothesis testing?

Answer 15

A Type II error occurs when the null hypothesis is accepted when it is actually false.

Question 16

What is the formula for calculating the coefficient of determination (R-squared)?

Answer 16

R-squared is calculated as the square of the correlation coefficient between two variables.

Question 17

What is the purpose of a scatter plot in statistics?

Answer 17

A scatter plot is used to visualize the relationship between two variables in a data set.

Question 18

What is the difference between a dependent and independent variable in statistics?

Answer 18

A dependent variable is the outcome being measured, while an independent variable is the factor that is being manipulated.

Question 19

What is the formula for calculating the coefficient of correlation?

Answer 19

The coefficient of correlation is calculated by dividing the covariance of two variables by the product of their standard deviations.

Question 20

What is the purpose of regression analysis in statistics?

Answer 20

Regression analysis is used to analyze the relationship between two or more variables and predict future outcomes.

Question 21

What is the difference between a one-tailed and two-tailed test in hypothesis testing?

Answer 21

In a one-tailed test, the rejection region is on only one side of the distribution, while in a two-tailed test, it is on both sides.

Question 22

What is the formula for calculating the margin of error in a confidence interval?

Answer 22

The margin of error is calculated by multiplying the critical value by the standard error.

Question 23

What is the purpose of ANOVA (Analysis of Variance) in statistics?

Answer 23

ANOVA is used to analyze differences among three or more groups by comparing variances.

Question 24

What is the difference between a null hypothesis and an alternative hypothesis?

Answer 24

The null hypothesis assumes no effect or difference, while the alternative hypothesis suggests that there is an effect or difference.

Question 25

What is the formula for calculating the z-score of a data point?

Answer 25

The z-score is calculated as the difference between the data point and the mean divided by the standard deviation.

Question 26

What is the formula for calculating the z-score of a data point?

Answer 26

The z-score is calculated as the difference between the data point and the mean divided by the standard deviation.