PSYC1040 Hypothesis Testing

With a significance level of .05, a significant result means that

• one can be 95% sure that the null hypothesis is true

• one can be 5% sure that the null hypothesis is true

• one can be 95% sure that the alternative hypothesis is true

• assuming the null hypothesis is true, the chance of getting the data is less than 5%

• assuming the alternate hypothesis is true, the chance of getting the data is less than 5%

A type I error occurs when the researcher:

• rejects the null hypothesis when it is false

• rejects the null hypothesis when it is true

• accepts the null hypothesis when it is true

• accepts the null hypothesis when it is false

• obtains a non-significant result

If the null hypothesis is true and the researcher declares their data to be not statistically significant, which of the following has occurred?

• Type I error

• Type II error

• Correct decision

• Type I and Type II error

• None of the above

In an experiment with a significance level set at 5% and assuming the null hypothesis is true, what is the probability of making a type I error?

• .005

• .05

• .00

• .95

• .095

If the null hypothesis is false, then:

• the decision to reject the null hypothesis constitutes a Type-I error

• the decision to reject the null hypothesis constitutes a Type-II error.

• the decision to accept the null hypothesis constitutes a Type-I error.

• the decision to accept the null hypothesis constitutes a Type-II error.

• all of the above

In hypothesis testing, if the null hypothesis is rejected, then this means that:

• an alternative hypothesis is true.

• the null hypothesis is true.

• the null hypothesis is false.

• the alternative hypothesis is true.

• any one of the above could be correct.

My population has a mean of 83 and a variance of 17. What can I conclude about my sample mean of 87, if N = 7?

• Z = 2.56, reject the null hypothesis

• Z = 0.97, retain the null hypothesis

• Z = 2.56, retain the null hypothesis

• Z = 0.97, reject the null hypothesis

• Z = 1.51, retain the null hypothesis

My population has a mean of 62 and a standard deviation of 6.25. Approximately what percentage of sample means (N = 11) would sit between 57 and 65?

• 28%

• 94%

• 72%

• 6%

• 51%