Answer:
81 pi cm^2
or approximately 254.34 cm^2
Step-by-step explanation:
The area of a circle is given by
A = pi r^2
A = pi (9)^2
A = 81 pi
Using 3.14 as an approximation for pi
A = 81 (3.14)
A =254.34 cm^2
First you distribute making it 4y-24=0
second you isolate the variable making it 4y=24
finally you divide by four giving you the answer of y=6
3 - 1/8a = 1/4
The goal is to isolate "a" and its coefficient to make the simplification process easier.
Start by subtracting 3 from both sides:
3 - 3 - 1/8a = 1/4 -3
-1/8a = 1/4 - 3
Next, multiply 3 by 4/4 to convert it into a fraction:
-1/8a = 1/4 - [3 • (4/4)]
-1/8a = 1/4 - 12/4
-1/8a = - 11/4
Multiply both sides by -8:
(-8) -1/8a = - 11/4 (-8)
a = 88/4 = 22
Therefore, a = 22.
<h2>
Answer with explanation:</h2>
Let
be the population mean lifetime of circulated $1 bills.
By considering the given information , we have :-

Since the alternative hypotheses is two tailed so the test is a two tailed test.
We assume that the lifetime of circulated $1 bills is normally distributed.
Given : Sample size : n=50 , which is greater than 30 .
It means the sample is large so we use z-test.
Sample mean : 
Standard deviation : 
Test statistic for population mean :-


The p-value= 
Since the p-value (0.0433834) is greater than the significance level (0.02) , so we do not reject the null hypothesis.
Hence, we conclude that we do not have enough evidence to support the alternative hypothesis that the average lifetime of a circulated $1 bill differs from 18 months.