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.
Its already an improper fraction.
If you mean mixed number it would be 7 4/7.
Hope this helps!:)
The difference between these temperatures for the sunset is found as 11 degrees.
<h3>What is temperature difference?</h3>
In science, the term Delta T (ΔT) refers to the temperature between two measuring points. The temperature varies according to time and/or location.
Some key features regarding the temperature difference are-
- Merus, for example, uses it to assess the effectiveness of such a heat exchanger.
- Or to evaluate the effectiveness of a heating or cooling system.
- A fourth letter of a Greek alphabet is, (Δ). Whereas is the capital letter symbol and the lower case letter.
- The sign is also used in mathematics. Describes the "difference" between any two changeable quantities. T is a value in a process that represents a difference between two observed temperatures.
Now, according to the question;
Let the initial temperature be 'T' = 4 degrees.
Let the final temperature be 't' = -7 degrees.
Therefore, the temperature difference is;
ΔT = T - t
= 4 - (-7)
= 4 + 7
ΔT = 11
Therefore, the difference between these temperatures is 11 degrees.
To know more about the temperature difference, here
brainly.com/question/24746268
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Answer:
12 and 28
Step-by-step explanation:
Represent the numbers using x and y. Then y - x = 16. (y is the larger one.)
Then 3y = 7x, and y = (7/3)x.
Substituting (7/3)x for y in y - x = 16, we get:
(7/3)x - x = 16.
Eliminate the fraction by multiplying all three terms by 3:
7x - 3x = 48, or 4x = 48, yielding x = 12. Then y = (7/3)(12) = 28.