Answer:
20.25π
Step-by-step explanation:
The circumference (C) of a circle is calculated using the formula
C = 2πr ← r is the radius
given C = 9π, then
2πr = 9π ( divide both sides by 2π )
r = ( cancel the π on numerator/denominator )
= 4.5
The area (A) of a circle is calculated using the formula
A = πr² = π × 4.5² = 20.25π
What.
WHAT.!?
your correct answer should be: z = (x - mean) / SD = (79 - 70) / 3 = 3
P (Z > 3)? = 1 - F (z) = 1 - F (3) = 0.00135 i hope this is helpful! :D