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:

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

something that characterises a right triangle is the fact that we may use pythagoras' theorem to find any one of its sides given that we have the length of the other two sides. here, we have the length of the hypotenuse, √(87) yd, and one other side, √(23) yd, thus we can easily find the length of the remaining side using pythagoras' theorem as defined below:

c^2 = a^2 + b^2, where c is the length of the hypotenuse, and a and b are the lengths of the other two sides.

thus, given that c = √(87) and a = √(23), we may substitute these into the formula we defined above to get:

c^2 = a^2 + b^2

(√87)^2 = (√23)^2 + b^2 (substitute c = √87 and a = √23 into the equation)

87 = 23 + b^2 (evaluate (√87)^2 = 87 and (√23)^2 = 23 - remember that the square root of a number, squared will equal that very same number)

64 = b^2 (subtract 23 from both sides)

√64 = b (take the square root of both sides)

8 = b (evaluate √64 = 8)

therefor, the length of the unknown leg in the right triangle is 8 yd (first answer).

both equations and proportions are better.