A sample of n = 25 individuals is selected from a population with µ = 80 and a treatment is administered to the sample. What is expected if the treatment has no effect?​Group of answer choices​The sample mean should be close to 80 and should lead you to reject the null hypothesis.​The sample mean should be very different from 80 and should lead you to reject the null hypothesis.​The sample mean should be close 80 and should lead you to fail to reject the null hypothesis.​The sample mean should be very different from 80 and should lead you to fail to reject the null hypothesis.

A researcher administers a treatment to a sample of participants selected from a population with µ = 80. If a hypothesis test is used to evaluate the effect of the treatment, which combination of factors is most likely to result in rejecting the null hypothesis?​Group of answer choices​A sample mean much different than 80 with α = .05​A sample mean near 80 with α = .05​A sample mean near 80 with α = .01​A sample mean much different than 80 with α = .01

A researcher administers a treatment to a sample of participants selected from a population with µ = 80. If the researcher obtains a sample mean of M = 88, given the same alpha level, which combination of factors is most likely to result in rejecting the null hypothesis?​Group of answer choices​σ = 5 and n = 25​σ = 10 and n = 50​σ = 10 and n = 25​σ = 5 and n = 50

Even if a treatment has no effect, it is still possible to obtain an extreme sample mean that is very different from the population mean. What outcome is likely if this happens?​Group of answer choices​Correctly reject H0.​Correctly fail to reject H0.​Fail to reject H0 and make a Type II error.​Reject H0 and make a Type I error.

If a treatment has a very small effect, then what is a likely outcome for a hypothesis test evaluating the treatment?​Group of answer choices​A Type II error​Correctly reject the null hypothesis​A Type I error​Correctly fail to reject the null hypothesis

A researcher expects a treatment to produce an increase in the population mean. The treatment is evaluated using a one tailed hypothesis test, and the test produces z = +1.85. Based on this result, what is the correct statistical decision?​Group of answer choices​The researcher should fail to reject H0 with either α = .05 or α = .01.​The researcher should reject the null hypothesis with α = .05 but not with α = .01.​The researcher should reject the null hypothesis with either α = .05 or α = .01.​The researcher should change α.