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 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
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
H1 :μ≠ 5
can be claimed to be :
e.can't say without knowing the sample size
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