"Formula of a circle" is too vague to be meaningful. Perhaps you meant, "Formula for the area of a circle in terms of its circumference."
The area of a circle in terms of its radius is A = πr^2. To put this formula to use, we have to know the radius of the circle. The circumference of a circle in terms of its radius is C = 2πr, so a formula for the radius is r = C / (2π).
Now let's find a formula for the area of a circle in terms of its circumference:
C C^2
A = πr^2 = π { ---------------- }^2 = ------------
2π 4π
or:
A = (C^2) / 4π
Answer:
Step-by-step explanation:
Answer:
Step-by-step explanation:
Yes!
The interval of 95% confidence, for normally distributed variables, is average +/- 2 * standard deviation:
(-2*standard deviation + average , average + 2*standard deviation)
(-2*18 + 62.5 , 2*18 + 62.5) = (-36 + 62.5 , 36 + 62.5) = (26.5 , 98.5)
Answer: option D)