600 *2*x + 150*4*x = 90
1200x + 600x = 90
1800x = 90
x = 90/1800 = 0.05
x = 5%
Answer: rate of interest = 5%
Answer:
d. The random variable is the number of years in which the temperature increased from the previous year.
Step-by-step explanation:
The random variable is the amount of years that have higher average temperatures than its previous year.
As the sample is from 5 years, the random variable can take values from 0 (where none of the years increase their average temperature from its previous year) to 4 (where every year increases the average temperature).
| x - 8| = 3
x - 8 = 3 - (x - 8) = 3
x = 3 + 8 -x + 8 = 3
x = 11 -x = 3 - 8
-x = - 5
x = 5
Minimum : 5% Maximum : 11% if u need them added it is 16%
Expected Mean, E(X), is obtained by multiplying each pair of

and its

and add up the answers
E(X) = (0×0.7) + (1×0.2) + (2×0.1) = 0.4
The formula to calculate the variance, Var(X), is given by E(X)² - (E(X))²
E(X²) = (0²×0.7) + (1²×0.2) + (2²×0.1) = 0+0.2+0.4 = 0.6
(E(X))² = (0.4)² = 0.16
Var(X) = 0.6 - 0.16 = 0.44
Translating these answers into the context we have
E(Y) = 0.4×500 = $200
Var(Y) = $110