Answer:
The formula to calculate standard deviation from probability is \sqrt(n*p*(1-p)). n is the sample size, and 200 in this case (number of putts for practice). p is 80% or 0.8, the probability that he can make it. So the standard deviation is \sqrt(200*0.8*(1-0.8)=\sqrt(200*0.8*0.2)=\sqrt(16)=4.
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Explanation:
↓↓↓↓↓↓↓↓↓↓
First you had to add by
from both sides of the equation.

Simplify it should be the correct answer.

Answer⇒⇒⇒⇒⇒r=2
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-Charlie
The most common verticle jump is 38 in.
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