Statistics and Probability Quiz

It is a proposed explanation, assertion, or assumption about a population parameter or about the distribution of a random variable

• Decision

• Statistics

• Probability

• Hypothesis

Which of the following describes an alternative hypothesis in a left-tailed test?

• 1. Ha > 100 

• 1. Ha < 100

• 1. Ha = 100 

• Ha ≠ 100

Which of the following is NOT a consideration in using z-test/statistic

• 1. Variance is known. 

• 1. Sample standard deviation is known.

• 1. The population mean is less than 30.

• Data are normally distributed

One-sample t-statistic is used instead of one-sample z-statistic when ___________

• 1. μ is known. 

• σ is known

• μ is unknown. 

• σ is unknown

If the variance is known, what test statistics is appropriate?

• 1. t-test

• z-test

• 1. two-tailed test

• one-tailed test

Based on the Central Limit Theorem, when the sample (n) is extremely large and variance is unknown, what is the statistical test to be used?

• 1. t-test

• z-test

• 1. two-tailed test

• one-tailed test

It is the probability of makin a type I error?

• 1. 0.05

• 0.01

• α   

• β

It is the probability of makin a type II error?

• 1. 0.05

• 0.01

• α   

• β

When is a Type II error committed?

• We reject null hypothesis that is true

• We reject a null hypothesis that is false

• We fail reject a null hypothesis that is true

• We fail to reject a null hypothesis that is false

When is a Type I error committed?

• We reject null hypothesis that is true

• We reject a null hypothesis that is false

• We fail reject a null hypothesis that is true

• We fail to reject a null hypothesis that is false