Question

A sample of 56 fish (Mogul liza species) were tested for zinc concentration (Environmental Monitoring and Assessment, 1993). The interval from 8.8 mg/g to 9.5 mg/g is the 95% confidence interval for the population mean zinc concentration. (The sample mean was 9.15.) Which following statements is the best interpretation for the meaning of this confidence interval? The probability that this confidence interval (8.8, 9.5) contains the true population mean is 0.95. In repeated sampling from this fish population, about 95% of the confidence intervals calculated from these samples will contain 9.15. We can be 95% sure that the true population mean zinc concentration is between 8.8 mg/g and 9.5 mg/g. The probability that this confidence interval (8.8, 9.5) contains the sample mean is 0.95. In repeated sampling from this fish population, about 95% of the confidence intervals calculated will contain 95% of the zinc concentrations of the fish. We can be sure that 95% of all Mogul liza species will have zinc concentrations between 8.8 mg/g and 9.5 mg/g.

Answer 1

Answer:

We can be 95% sure that the true population mean zinc concentration is between 8.8 mg/g and 9.5 mg/g.

Step-by-step explanation:

Given that

N = Sample = 56

Confidence Interval = 95%

Mean Interval = 8.8 mg/g to 9.5 mg/g

UB = Upper Bound = 9.5mg/g

LB = Lower Bound = 8.8mg/g

The sample mean was 9.15mg/g

The sample mean is gotten from ½(UB + LB)

Sample Mean = ½(8.8 + 9.5)

Sample Mean = ½ * 18.3

Sample Mean = 9.15mg/g

From the definition of confidence Interval;

"Confidence Interval is a range of values so defined that there is a specified probability that the value of a parameter lies within it"

This means that the best interpretation of the data given is "the mean value of the 56 sample of fishes is between 8.8mg/g and 9.5mg/g;"

With 8.8mg/g as the lower bound and 9.9mg/g as the upper bound.