Answer:
C
Step-by-step explanation:
Answer: in 95% of races, his finishing time will be between 62 and 64 seconds.
Step-by-step explanation:
The empirical rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean . The empirical rule is further illustrated below
68% of data falls within the first standard deviation from the mean.
95% fall within two standard deviations.
99.7% fall within three standard deviations.
From the information given, the mean is 63 seconds and the standard deviation is 5 seconds.
2 standard deviations = 2 × 0.5 = 1
63 - 1 = 62 seconds
63 + 1 = 64 seconds
Therefore, in 95% of races, his finishing time will be between 62 and 64 seconds.
Using the cosine double angle formula,
(Note I took the positive case since 
terminates in the first quadrant)
Using the Pythagorean identity,
(Note I took the positive case since terminates in the first quadrant)
Answer:
r = 2.55
Step-by-step explanation:
The formula for finding the radius of a circle using the area is r = √A/π
with the r being the radius. the A being the area, and the π being pi (we'll use 3.14).
So the equation should look like this:
r = √(20.4/3.14)
Find the quotient of 20.4/3.14 and round to the nearest tenth
r = √6.5
Find the square root and round to the nearest hundredth
r = 2.55
