John is twice as old as Mary. The sum of their ages is 21. How old is Mary?
1 answer:
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Answer:
Option A is correct.
y = 35.4 bushels per acre when rainfall = 7.1 inches
Step-by-step explanation:
An image of the steps to obtain the equation that relates x to y is attached to this answer.
n = number of variables = 9
μₓ = mean of variable x (rainfall in inches)
μᵧ = mean of variable y (yield in bushels per acre)
σₓ = standard deviation of variable x (rainfall in inches)
σᵧ = standard deviation of variable y (yield in bushels per acre)
y = 4.379x + 4.268
when x = 7.1
y = 4.379(7.1) + 4.268 = 35.3589 = 35.4 bushels per acre.
