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:
d = 3/7 = 0.429
d = 1
Step-by-step explanation:
Answer:
18
Step-by-step explanation:
180-160 = 20 which equals the exterior angle
the sum of exterior angles is 360 so 360/20 = the number of sides as there is an exterior angle for every side
360/20 = 18
Answer:
sin(B) = 12/13
cos(B) = 5/13
tan(B) = 12/5
csc(B) = 13/12
sec(B) = 13/5
cot(B) = 5/12
Step-by-step explanation:
If ABC is a right triangle, assuming that ∠C = 90°, then the segment AB =13 is the hypotenuse and the other two sides are:

The six trigonometric functions of angle B are:

Answer:
x=15
Step-by-step explanation:
(10*9)/6=10*x/10
90/6=x
15=x