can you comment the question?
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.
The answer is in decimal formal in the file below
Hi there!
We know that RST is an equilateral(all 3 sides the same length) triangle, and is therefore equiangular(all 3 angles the same value). Therefore, angle S and is equal to one-third of the triangle's angle measure.
180/3=60
60=7x+4
56=7x
x=8
-AwesomeRepublic :)