Hi

I need some help with questions from prevous exam..they dont have answers

can anyone help please?

Q1. A significance test was performed to test the null hypothesis Ho: μ=2 versus the alternative hypothesis H1: μ≠ 2. The test statistic is z = 1.40. The p-value for this test is approximately

a.0.08

b.0.003

c.0.92

d.0.70

e.0.16

Q2.

A significance test gives a p-value of 0.04. From this we can:

a.reject the null hypothesis at the 1% level.

b.say that the difference between our estimate and the hypothesized value is most likely to be due to sampling variability alone.

c.reject the null hypothesis test at the 5% level but not at the 1% level

d.say that the probability that the null hypothesis is false is 0.04

e.say that the probability that the null hypothesis is true is 0.04

Q3.

A 95% confidence interval for the mean (μ) of a random variable, based on the t-distribution, is found to be (4.2, 4.8).

With minimal further calculations, the p-value for a test of

Ho :μ=5

H1 :μ≠ 5

can be claimed to be :

a.< 0.05

b.< 0.001

c.< 0.01

d.> 0.05

e.can't say without knowing the sample size

Q4.

A study was undertaken to compare moist and dry storage conditions for their effect on the moisture content(%) of white pine timber. The report on the findings from the study included the following statement:

"The study showed a significant difference ( observed difference =7.85%-6.75%=1.1%; p-value=0.023) in the moisture content of the pine timber under different storage conditions. Level of Significance (α) for the test was 5%"

Based on this information, which of one the following statements is necessarily FALSE?

a. If the researchers used a large enough sample size then even a tiny difference could result in a statistically significant difference

b. If this study was repeated 100 times over, then we would expect to (incorrectly) conclude there was a difference in the storage methods for approximately 5 of the 100 studies (that is, 5% of the time we would say there was a difference in the storage methods when, in fact, there was none).

c. A statistically significant difference of 1.1% in the moisture content of the white pine is not necessarily a difference of practical importance

d. The observed difference between the mean moisture contents (1.1%) is unlikely to be due to chance alone.

e. The probability that there is no difference between moist and dry storage conditions is 0.023