Answer:

Step-by-step explanation:
Circumference is the perimeter of a circle. It can be found using the formula:

However, we are given the radius.
- The radius measures from the center to the edge of the circle.
- The diameter measures from edge to edge through the center.
- So, the diameter is twice the radius, or d=2r
The formula can be rewritten as:

We know the circumference is 25.12 inches.

Let's round pi to 3.14

We want to solve for the radius, so we must isolate it.
Divide both sides by 3.14 because the inverse of multiplication is division.


Divide both sides by 2.


The radius of the disc is <u>4 inches.</u>
C = 2m^2 + m
D = 2 - 6m + 2m^2
2C = 2(2m^2 + m) = 4m^2+2m
2D = 2(2-6m+2m^2) = 4-12m+4m^2
2C - 2D =
4m^2+2m-(4-12m+4m^2) =
4m^2+2m-4+12m-4m^2 =
0m^2 + 14m -4 =
14m - 4
Answer: a=1.4
Step-by-step explanation:
move the 0.1a to the other and the 7 to the other side which will make the 7 positive and the 0.1a negative.
5a-0.1= 4.9a
-0.14+7=6.86
dive both sides by 4.9 and you get
a=1.4
A negative number is not considered a whole number...so ur answer is -229
Answer:
a

b

Step-by-step explanation:
From the question we are told that
The mean value is 
The standard deviation is 
Considering question a
The sample size is n = 9
Generally the standard error of the mean is mathematically represented as

=>
=> 
Generally the probability that the sample mean hardness for a random sample of 9 pins is at least 51 is mathematically represented as



=> 
From the z table the area under the normal curve to the left corresponding to 2.5 is

=> 
=> 
Considering question b
The sample size is n = 40
Generally the standard error of the mean is mathematically represented as

=>
=> 
Generally the (approximate) probability that the sample mean hardness for a random sample of 40 pins is at least 51 is mathematically represented as

=> 
=> 
From the z table the area under the normal curve to the left corresponding to 5.2715 and
=> 
So

=> 