Hello,
y=5+3*cos (2(x-π/3))
The function is periodic with periode=2π.
-1<=cos (2(x-π/3))<=1
==>-1*3<=3*cos (2(x-π/3))<=3*1
==>5-3<=5+3cos(2(x-π/3))<=5+3
==>2<= y<=8
We first calculate the z-score corresponding to x = 1075 kWh. Given the mean of 1050 kWh, SD of 218 kWh, and sample size of n = 50, the formula for z is:
z = (x - mean) / (SD/sqrt(n)) = (1075 - 1050) / (218/sqrt(50)) = 0.81
From a z-table, the probability that z > 0.81 is 0.2090. Therefore, the probability that the mean of the 50 households is > 1075 kWh is 0.2090.
For this question you would have to expand the numbers to the thounsandths
so it can be 9.181, 9.182, 9.183 and so on
Answer:
0.1199 = 11.99% probability that at least 5 of them did not finish the marathon
Step-by-step explanation:
For each runner, there are only two possible outcomes. Either they finished the marathon, or they did not. The probability of a runner completing the marathon is independent of any other runner. This means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
97.4% finished:
This means that 100 - 97.4 = 2.6% = 0.026 did not finish, which means that 
100 runners are chosen at random
This means that 
Find the probability that at least 5 of them did not finish the marathon
This is:

In which









0.1199 = 11.99% probability that at least 5 of them did not finish the marathon
(5.5x + 6.2y) + (4.3x + 8.3z) + (1.6z - 5.ly)
Combine Like Terms
9.8x + 1.1y + 14.5z
So the perimeter is
9.8x + 1.1y + 14.5z