Aphysicist examines 28 sedimentary samples for mercury concentration. the mean mercury concentration for the sample data is 0.863 cc/cubic meter with a standard deviation of 0.0036. determine the 98% confidence interval for the population mean mercury concentration. assume the population is approximately normal. step 2 of 2: construct the 98% confidence interval. round your answer to three decimal places.

Step-by-step explanation:

The confidence interval for population mean is given by :-

, where n=sample size

= sample mean

=sample standard deviation

= critical t-value (for two tailed )

Let   be the confidence interval for the population mean mercury concentration.

As per given , we have

Sample size : n= 28

degree of freedom = 27   [df=n-1]

Sample mean : cc/cubic meter

Sample standard deviation : s= 0.0036

Significance level :

Critical two-tailed test value :

 (Using t-distribution table.)

We assume the population is approximately normal.

Now, the 98% confidence interval for the population mean mercury concentration will be :-

Required confidence interval :

triangle abc is reflected on the line x=-6.5 then reflected again on the x axis

step-by-step explanation:

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls