It would be x = 2 2/3 because
2 2/3 - 2 = 2/3
6 x 2/3 = 4
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.
Let's assume the unknown number is x and as another one is 5 times the number then second number is 5x
》x × 5x = 245
》5x square =245
》x square =245÷5
》x square =49
》x=7
So 5x = 5×7=35
We already know that the box has an area of 100 sq. inches. All we have to do now is subtract the area of the 4 circles from the area of the box.
The formula for a circle's area is 
. We already know the radius, so one circle has an area of 12.56 units (4π in terms of pi). There are 4 circles, making your final equation 
.
