IF YOU CAN PROVIDE STEPS IT WILL HELP ME UNDERSTAND. THANKS IN ADVANCE. 1.. When
ID: 3131084 • Letter: I
Question
IF YOU CAN PROVIDE STEPS IT WILL HELP ME UNDERSTAND. THANKS IN ADVANCE.
1.. When is it OK to use a confidence interval instead of computing a p value in a hypothesis test?
Select one:
a. In any significance test.
b. In any hypothesis test with a two-sided alternative hypothesis.
c. Only when the hypothesized value of the parameter is not in the confidence interval.
d. Only when you are conducting a hypothesis test with a one-sided alternative. e. Only when doing a test for a single population mean.
2. In order to compare two kinds of feed, thirteen pigs are split into two groups, and each group received one feed. The following are the gains in weight (kilograms) after a fixed period of time:
Feed A: 8.0 7.4 5.8 6.2 8.8 9.5
Feed B: 12.0 18.2 8.0 9.6 8.2 9.9 10.3
We wish to test the hypothesis that Feed B gives rise to larger weight gains. Assume the variances to be unequal. The output from SAS is as follows:
Variable: GAIN Weight gain (kg)
FEED N Mean Std Dev Std Error
----------------------------------------------------
a 6 7.6166666667 1.445567939 0.5901506398
b 7 10.88571429 3.49400848 1.32061107
Variances T DF Prob>|T|
---------------------------------------
Unequal -2.2600 8.2 0.0528
Equal -2.1302 11 0.0566
For H0: Variances are equal, F' = 6.85 DF = (6,5) Prob>F' = 0.0520
The appropriate test statistic and p-value are:
Select one:
a. t = -2.2600; p-value = 0.0528
b. t =-2.2600; p-value = 0.0264
c. t = -2.1302; p-value = 0.0566
d. t = -2.1302; p-value = 0.0283
3. Which of the following statements is false?
I. We use one-sample procedures when our samples are equal in size but aren't independent.
II. Everything else being equal, a confidence interval based on 15 degrees of freedom will be narrower than one based on 10 degrees of freedom.
III. The samples used in all two-sample procedures must be of the same size.
Select one:
a. I only
b. II only
c. III only
d. I and III only
e. None of the above gives the correct response.
Explanation / Answer
2)
The appropriate test statistic is t test and p-value are:
a. t = -2.2600; p-value = 0.0528
3)
All are wrong
I. We use one-sample procedures when our samples are equal in size but aren't independent. it is wrong because in one sample procedure we use only one sample
II. Everything else being equal, a confidence interval based on 15 degrees of freedom will be narrower than one based on 10 degrees of freedom. this satatement is wrong since 15 df is wider than 10df
III. The samples used in all two-sample procedures must be of the same size. It is also false since for independent sample sizes are not same