Step-by-step explanation:
Use Pythagorean theorem:
c² = a² + b²
Here, c = 42 and a = 31.
42² = 31² + b²
b = √803
b ≈ 28.3
There is no explicit formula for interest rate, so it must be found by some sort of solver. Here a TI-84 work-alike calculator financial app has been used to find the interest rate (APR) to be 7.5%.
The loan amount is 4000 less 8% of 4000, which is .08*4000 = 320. That is, the loan amount is 4000 -320 = 3680.
We need to find the area under the standard normal curve that is to the right of 66.
Various ways of doing this include the following:
1) Calculator: normalcdf(66, 10000, 100, 15) = 0.988, or 98.8%
2) z-scores (using a published table of z scores)
66 - 100
a) Find the z score corresponding to 66. It is z = -------------- = -2.27
15
b) Find the area under the st. normal curve to the left of z=-2.27 (it is 0.012). Subtract that area from the total area, 1.000. The result will be the answer to this question.
Answer:
5
Step-by-step explanation:
z = -3 + 8 = 5
