Question

24. a) The average height od sunflowers in a field is 64 in. with a standard deviation of 3.5 in. On a piece of paper, draw a normal curve for the distribution, including the values of the horizontal axis at one, two, and three standard deviations from the mean. Describe your drawing in as much detail as possible, and explain how you came up with each of your labels. b) If there are 3,000 plants in the field, approximately how many will be taller than 71 in.? Explain how you got your answer.

Answer 1

Μ = 64 
σ = 3.5 

a) 

μ - 3σ = 53.5 
μ - 2σ = 57.0 
μ - σ = 60.5 
μ = 64.0 
μ + σ = 67.5 
μ + 2σ = 71.0 
μ + 3σ = 74.5 

b) 

(71 - 64)/3.5 = 2.0 
z = 0.9772 
n = 3000*(1 - 0.9772) 
≈ 68
Hope this helps!