Question

As part of a study of the treatment of anemia in cattle, researchers measured the concentration of selenium in the blood of 36 cows who had been given a dietary supplement of selenium (2 mg/day) for one year. The cows were all the same breed and had all borne their first calf during the year. The mean selenium concentration was 6.21 μg/dl and the standard deviation was 1.84 μg/dl.16 Construct a 95% confidence interval for the population mean.

Answer 1

Explanation:

Given that a part of a study of the treatment of anemia in cattle, researchers measured the concentration of selenium in the blood of 36 cows who had been given a dietary supplement of selenium (2 mg/day) for one year.

If x is the selenium concentration then

X has mean= 6.21 mg/dl

and std dev = 1.84

Sample size n = 36

std error of sample =
`(1.84)/(√(36) ) \\=0.307`

Margin of error for 95%

`1.96(0.307)=0.602`

Confidence interval =
`(6.21-0.605, 6.21+0.605)\\= (5.605, 6.815)`