Question

Preliminary data analyses indicate that the assumptions for using pooled​ t-procedures are satisfied. Independent random samples of 104 plots with cropland and 98 plots with grassland yielded the given summary statistics for the number of species of bird. At the 55​% significance​ level, do the data provide sufficient evidence to conclude that a difference exists in the mean number of species in the two​ regions?

Cropland Grassland x overbar 1 equals 14.44 x overbar 2 equals 15.66 s 1 equals 4.75 s 2 equals 4.64 n 1n1equals=104 n 2n2equals=98

Let

mu 1μ1

be the mean number of species of bird in the cropland

mu 2μ2

the mean number of species in the grassland. What are the correct hypotheses to​ test?

A.

Upper H 0H0​:

mu 1μ1equals=mu 2μ2

Upper H Subscript aHa​:

mu 1μ1greater than>mu 2μ2

B.

Upper H 0H0​:

mu 1μ1equals=mu 2μ2

Upper H Subscript aHa​:

mu 1μ1not equals≠mu 2μ2

C.

Upper H 0H0​:

mu 1μ1less than<mu 2μ2

Upper H Subscript aHa​:

mu 1μ1equals=mu 2μ2

D.

Upper H 0H0​:

mu 1μ1not equals≠mu 2μ2

Upper H Subscript aHa​:

mu 1μ1equals=mu 2μ2

E.

Upper H 0H0​:

mu 1μ1greater than>mu 2μ2

Upper H Subscript aHa​:

mu 1μ1equals=mu 2μ2

F.

Upper H 0H0​:

mu 1μ1equals=mu 2μ2

Upper H Subscript aHa​:

mu 1μ1less than<mu 2μ2

Compute the test statistic.

tequals=nothing

​(Round to three decimal places as​ needed.)

Determine the critical value or values.

nothing

​(Round to three decimal places as needed. Use a comma to separate answers as​ needed.)

What is the conclusion of the hypothesis​ test?

Since the test statistic

is

is

is not

in the rejection​ region,

do not reject

do not reject

reject

Upper H 0H0.

Conclude that the data

provide

provide

do not provide

sufficient evidence that a difference exists in the mean number of species in the two regions.

Answer 1