Answer: C.-1.5
Step-by-step explanation:
Given: The burning time of a very large candle is normally distributed with mean
of 2500 hours and standard deviation
of 20 hours.
Let X be a random variable that represent the burning time of a very large candle.
Formula: 
For X = 2470

So, the z-score they corresponds to a lifespan of 2470 hours. =-1.5
Hence, the correct option is C.-1.5.
Answer:
The width of the rectangle is 14'8", and the length is 33'4"
Step-by-step explanation:
We're given two pieces of information:
The length is eight more than twice the width:

The perimeter is 96 feet:

We also need to apply one more piece of information that is not provided here, and that is the relationship between the perimeter of a rectangle, and it's length and width:

We can solve for w by plugging the other two values into the last:

Now we can find the length by plugging w into the first equation:

One third of a foot is four inches, so the width is 14'8" and the length is 33'4"
To make sure our answer is correct, we should plug those numbers back into the area equation and see if we're right:

So we know our answer's correct
The percentage of 15% of 9 is 60% (I think)
Answer:
Option B is correct
the degree of rotation is, 
Step-by-step explanation:
A rotation matrix is a matrix that is used to perform a rotation in Euclidean space.
To find the degree of rotation using a standard rotation matrix i.e,

Given the matrix: 
Now, equate the given matrix with standard matrix we have;
= 
On comparing we get;
and
As,we know:

we get;

and

we get;

Therefore, the degree of rotation is, 
Answer:
4:50
Step-by-step explanation: