Statistics and Probability Reviewer

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

• Decision

• Hypothesis

• Probability

• Statistics

What is the term for the probability of making an incorrect decision about the null hypothesis

• Level of acceptance

• Level of error

• Level of hypothesis

• Level of significance

Which of the following describes an alternative hypothesis using two-tailed test?

• An alternative hypothesis using a two-tailed test states that there is no difference between the groups being compared.
• An alternative hypothesis using a two-tailed test states that there is a difference between the groups being compared, without specifying the direction of the difference.
• An alternative hypothesis using a two-tailed test specifies the exact magnitude of the difference between the groups.
• An alternative hypothesis using a two-tailed test only considers one group for comparison.

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

• The alternative hypothesis in a left-tailed test describes that the population parameter is less than the hypothesized value.
• The alternative hypothesis states that the population parameter is within a specific range around the hypothesized value.
• The alternative hypothesis states that the population parameter is equal to the hypothesized value.
• The alternative hypothesis states that the population parameter is greater than the hypothesized value.

When is a Type I error committed?

• We reject a null hypothesis that is true.

• We reject a null hypothesis that is false.

• We fail to reject a null hypothesis that is true.

• We fail to reject a null hypothesis that is false.

When is a Type II error committed?

• We reject a null hypothesis that is true.

• We reject a null hypothesis that is false.

• We fail to reject a null hypothesis that is true.

• We fail to reject a null hypothesis that is false.

Which of the following population parameters is used a s symbol for the mean or average population?

• theta (θ)
• sigma (σ)
• mu (μ)
• lambda (λ)

Which of the following statements best describes a parameter?

• It describes the sample.   

• It describes the population.

• It describes the hypothesis.

• It describes the researcher.

What is the parameter that represents the average height of a one-year-old child as 29 inches?

• a one-year-old child

• the mean height of 33 inches

• the average height of 29 inches

• a random sample of 30 children

What statistical test should be used when the sample size is extremely large and the variance is known according to the Central Limit Theorem?

• Chi-square test
• ANOVA
• T-test
• Z-test