Question

1- Choose the functions that should be used to test whether your dataset meets the assumptions for a two-sample t-test.

Select one or more:

a.

mean()

b.

normalTest()

c.

qt()

d.

var.test()

e.

var()

2- Which of the following is the name of a mandatory argument to the function read.csv in R?

Select one:

a.

file

b.

sep

c.

header

d.

quote

3-

Match the type of comparison to its appropriate null hypothesis.

The sample mean is not different from an expected value.	Answer 1Choose...one-sample t-test or Paired t-test or Unpaired t-test (two-sample t-test)
The sample means between two correlated samples are not different.	Answer 2Choose...one-sample t-test or Paired t-test or Unpaired t-test (two-sample t-test)
The means from two independent samples are not different.	Answer 3Choose...one-sample t-test or Paired t-test or Unpaired t-test (two-sample t-test)

4-

Match the test statistic equations to the correct type of t-test

	Answer 1Choose...paired t-test or one-sample t-test or two-sample t-test (unpaired t-test)
	Answer 2Choose...paired t-test or one-sample t-test or two-sample t-test (unpaired t-test)
	Answer 3Choose...paired t-test or one-sample t-test or two-sample t-test (unpaired t-test)

5- we analyzed the data for dissolved oxygen levels in 18 streams with mudfish and 23 streams without mudfish. The data were in the format of one column containing the values and the other column containing whether mudfish were present or absent. The first six rows of the dataset looked like this:

  mudfish    do
1  absent 2.325
2  absent 2.960
3  absent 2.400
4  absent 3.160
5  absent 4.370
6  absent 5.075

Would the following line of code be appropriate to test the null hypothesis that the mean dissolved oxygen levels were different in streams with or without mudfish? Assume the dataset is saved in a data.frame called 'dat'.

t.test(dat$do~dat$mudfish,var.equal=FALSE)

Select one:

True

False

Answer 1

1- Choose the functions that should be used to test whether your dataset meets the assumptions for a two-sample t-test.

Select one or more:

a.

 mean()

b.

  normalTest()

c.

 qt()

d.

  var.test()

e.

 var()

2- Which of the following is the name of a mandatory argument to the function read.csv in R?

Select one:

a.

  file

b.

 sep

c.

 header

d.

 quote

3-

Match the type of comparison to its appropriate null hypothesis.

The sample mean is not different from an expected value.	Answer 1Choose...one-sample t-test
The sample means between two correlated samples are not different.	Answer 2Choose... Paired t-test
The means from two independent samples are not different.	Answer 3Choose... Unpaired t-test (two-sample t-test)

4. No equations are provided.

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Thank you! :)