Answer:
? = 13
Step-by-step explanation:
Using Pythagoras' identity in the right triangle
?² = 5² + 12² = 25 + 144 = 169 ( take the square root of both sides )
? =
= 13
Answer:
a) 0.4164
Step-by-step explanation:
Mean lifespan (μ) = 18.8 days
Standard deviation (σ) = 2 days
For any given lifespan 'X', the z-score is:

For X=12.04 days:

A z-score of -3.38 falls in the 0.036-th percentile of a normal distribution.
For X=18.38 days:

A z-score of -3.38 falls in the 41.68th percentile of a normal distribution.
The probability that a butterfly lives between 12.04 and 18.38 days is

Answer:
Step-by-step explanation:
Area of sector = angle/360 * pi * r^2
7.1 = 40/360 * 22/7 * r^2
7.1 = 1/9 * 22/7 * r^2
63.9 = 22r^2/7
r^2 = (7 * 63.9)/22
r^2 = 20.331818181818
r = square root of 20.331818181818
r = 4.51
d = r * 2 = 4.51 * 2 = 9.02
50 days needed for 10 million new account
5 days for 1 million
1 day for 0.2 million