Question

Toxaphene is an insecticide that has been identified as a pollutant in the Great Lakes ecosystem. To investigate the effect of toxaphene exposure on animals, groups of rats were given toxaphene in their diet. An article reports weight gains(in grams) for rats given a low dose (4ppm) and for control rats whose diet did not include the insecticide. The sample standard deviation for 23 female control rats was 32g and for 20 female low-dose rats was 54g. Does this data suggest that there is more variability in low-dose weight gains than in control weight gains? Assuming normality, carry out a test of hypotheses at significance level .05.

Answer 1

Check the explanation

Explanation:

The details of the given samples are as follows:

Low dose. Number numbers of rats 20

The standard deviation .
`S_1`=54g

Control:

Number of rats
`N_2`=23

The standard deviation
`S_1`=32g

`H_0`: there is no more variability in low — dose weight gains than in the control weight gins

`H_1`: There is mere In-viability in low — dose weight gains than in control weight gains

>4 The level of significance.

a= 0.05 The test statistic to test the above hypothesis is Larger variance Smaller variance

The critical value of F (19.22) dr and at 0.05

significance level is 2.0837

The P-Value is 0.01 The test significance value is greater the the critical level is 20837.

Also. the 8-value is less then the significance level Hence, we reject the null hypothesis.

Therefore, we conclude that there is sufficient evidence to conclude that there is more variability in low — dose weight gains than in control weight gains .