Answer:
a. 254.34, b. 56.52
Step-by-step explanation:
a. A = πr^2,
A = 3.14(9^2)
A = 3.14*81
A = 254.34
b. C = πd
C = 18*3.14
C = 56.52
Z = (x - m)/s
z = (38-40)/8
z = -2/8
z = -1/4
z = -0.25
The z score is -0.25
Independent variable (IV): something the scientist can change.
Thus, in this case, the IV can be the weight of the person.

change

given you

making x the subject by transferring the -19 to the right hand side of the equation


dividing through by 5


{
}
also given

change the operation sign to =



dividing through by -4


so the truth set is
{x:x>9/4}.
The < sign changes to > because we divided by a negative number when solving for x