Answer:
Standard error
Step-by-step explanation:
The standard deviation of the distribution of sample means is called the standard error of the means.
It is denoted by:
The standard error is calculated using the formula:
where n is the sample size and is the population standard deviation.
Answer and Step-by-step explanation:
Considering the table attached.
(a) over 9.5 kg;
μ = 8
σ = 0.9
z = 9.5 - 8/0.9 ≈ 1.67
P (Z > 1.67) = 0.5 - P(0<Z<1.67) = 0.5 - 0.4525 = 0.0475
(b) at most 8.6 kg;
z = 8.6-8/0.9 ≈ 0.67
P(Z < 0.67) = 0.5 + P(0<Z<0.67) = 0.5 + 0.2486 = 0.7486
(c) between 7.3 and 9.1 kg.
z₁ = 7.3-8/0.9 ≈ -0.78
z₂ = 9.1 - 8/0.9 ≈ 1.22
P(-0.78 < Z < 1.22) = P(0 < Z < 0.78) + P(0 < Z < 1.22) = 0.2823 + 0.3888 = 0.6711
