Question

A laboratory scale is known to have a standard deviation of Ï = 0.001 gram in repeated weighings. Scale readings in repeated weighings are Normally distributed, with mean equal to the true weight of the specimen. A particular specimen is weighed 8 times on this scale. The average weight is x ¯ = 4.1602 grams. A 99% confidence interval for the true weight of the specimen is:_______

Answer 1

Answer:

the confidence interval for the true weight of the specimen is;

4.1593 ≤ μ ≤ 4.1611

Step-by-step explanation:

We are given;

Standard deviation; σ = 0.001

Sample size; n = 8

Average weight; x¯ = 4.1602

We are given a 99% confidence interval and the z-value at this interval is 2.576

Formula for confidence interval is;

CI = x¯ ± (zσ/√n)

Plugging in the relevant values, we have;

CI = 4.1602 ± (2.576 × 0.001/√8)

CI = 4.1602 ± 0.000911

CI = (4.1602 - 0.000911), (4.1602 + 0.000911)

CI ≈ (4.1593, 4.1611)

Thus, the confidence interval for the true weight will be expressed as;

4.1593 ≤ μ ≤ 4.1611

Where μ represents the true weight