μ = 300,90% below 500; σ = ?
A)450
B)1.28
C)0.90
D)156.25
E)15.63

Name: μ = 300,90% below 500; σ = ? A)450 B)1.28 C)0.90 D)156.25 E)15.63
Brand: Quizplus
Rating: 4.9 (29 reviews)

Question

Quizplus · Accepted Answer

To find the standard deviation (σ), we use the z-score formula for a normal distribution. Given that 90% of the data is below 500, we find the z-score for 90% which is approximately 1.28. Using the formula: z = (X - μ) / σ, we solve for σ: 1.28 = (500 - 300) / σ, which gives σ = 156.25.

μ = 300,90% Below 500; σ =