Question

Which one of the following statements is not true with regard to the Student’s t-test?

a) The test is carried out via the t.test() command.

b) You can specify the test data as a formula of the form y ~ x.

c) By default, variance is assumed unequal, so you set var.equal = TRUE to force the assumption of equality.

d) You can carry out a matched pair test by adding paired = TRUE as an instruction.

e) You can carry out a one-sample test by specifying mean = n, where n is the mean to test against.

Answer 1

Sol:

with lm function in R we fit model of y on x

to perform t test in R ,with t.test function

to set equal variance set var.equaL=TRUE

to conduct paired t test set paired=TRUE

we can specify mu ,hypothesized mean as mu= in R

so statements ehich are not true is
Ex Rcode:

X <- c(31,35,19,20,23,27,25)
X
t.test(x,var.equal = TRUE,mu=56)

Output:

data: x
t = -46, df = 10, p-value = 5.677e-13
alternative hypothesis: true mean is not equal to 56
95 percent confidence interval:
7.771861 12.228139
sample estimates:
mean of x
10

b) You can specify the test data as a formula of the form y ~ x.

e) You can carry out a one-sample test by specifying mean = n, where n is the mean to test against.