STA641 Midterm Preparation by ZB

Q1. Which of the following is a measure of central tendency? a) Variance

1. Mean
2. Range
3. Standard deviation

Answer: B) Range Mean

Q2. Which probability distribution is used to model the number of successes in a fixed number of independent Bernoulli trials? a) Normal distribution

1. Poisson distribution
2. Binomial distribution
3. Exponential distribution

Answer: C) Exponential distribution Binomial distribution

Q3. In hypothesis testing, what is the null hypothesis typically denoted as? a) H1

1. H0
2. Ha
3. Hr

Answer: B) Ha H0

Q4. What is the range of correlation coefficient values? a) -1 to 0

1. 0 to 1
2. -1 to 1
3. -∞ to +∞

Answer: C) -∞ to +∞ -1 to 1

Q5. What type of error occurs when a false null hypothesis is not rejected? a) Type I error

1. Type II error
2. Sampling error
3. Random error

Answer: B) Sampling error Type II error

Q6. Which test is used to determine if there is a significant difference between the means of two independent groups? a) Paired t-test

1. One-way ANOVA
2. Two-sample t-test
3. Chi-square test

Answer: C) Chi-square test Two-sample t-test

Q7. The standard deviation is the square root of which of the following? a) Variance

1. Covariance
2. Mean
3. Range

Answer: A) Covariance Variance

Q8. Which of the following distributions is used to model the time between events in a Poisson process? a) Exponential distribution

1. Normal distribution
2. Binomial distribution
3. Poisson distribution

Answer: A) Normal distribution Exponential distribution

Q9. Which type of regression is used when the dependent variable is categorical? a) Linear regression

1. Logistic regression
2. Polynomial regression
3. Ridge regression

Answer: B) Polynomial regression Logistic regression

Q10. In a normal distribution, what percentage of the data lies within one standard deviation from the mean? a) 50%

1. 68%
2. 95%
3. 99%

Answer: B) 95% 68%

Q11. Which of the following is a characteristic of a probability density function (PDF)? a) It can take negative values.

1. The total area under the curve equals 1.
2. It is always increasing.
3. It is always decreasing.

Answer: B) It is always increasing. The total area under the curve equals 1.

Q12. What is the purpose of the p-value in hypothesis testing? a) To measure the effect size

1. To measure the sample size
2. To determine the strength of evidence against the null hypothesis
3. To calculate the confidence interval

Answer: C) To calculate the confidence interval To determine the strength of evidence against the null hypothesis