Help! Applied Calculus
Suppose a tractor purchased at a price of $60,000 is to be depreciated by the double declining-balance method over a 10-year period. It can be shown that the rate at which the book value will be decreasing is given by
R(t) = 13988.61e−0.22614t (0 ≤ t ≤ 10)
dollars/year at year t. Find the amount by which the book value of the tractor will depreciate over the first 7 years of its life. (Round your answer to the nearest dollar.)

your answer is  

a.

5

step-by-step explanation:

wow ok so the answer is 1k or just k

because of combining like terms xd

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.

x = 1/2

step-by-step explanation:

hope this !