Answer: 4
Step-by-step explanation:
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:
3/7
Step-by-step explanation:
The number of possible results are;
1, 2 , 3 , 4 , 5, 6 , 7 = 7
odd numbers here are;
1, 3 , 5 and 7
non-odd numbers are 2, 4 and 6
So the section not labeled with an odd number is 3
Hence the probability here is that;
3/7
Given the expression (8+3i)+(-2+i)
We need to simplify it.
(8+3i)+(-2+i)
First we have to remove the parenthesis.
8+3i-2+i
As we know that multiplication of positive and negative is negative.
Now we will add or subtract like terms. Like terms means here i with i and constant term with constant term. So here we will add 3i and i. Also subtract 2 from 8.
8-2 +3i+i
6+4i
We have got the required answer.
The simplified answer is 6+4i.