Answer:
#20 is irrational, #24 is 33/100, and #25 is 0
Step-by-step explanation:
Volume = Length x Width x Height
V= 7.5 ft x 4.2 ft x w fr
The width is 2 as listed.
V= 7.5ft x 4.2ft x 2ft
V=63
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
Answer:
The system is inconsistent
Step-by-step explanation:
Given the matrix system solutions in the attachment, we can see that the coefficient of the matrix rank has become zero. This shows that it has no solution.
Answer:
There are 392 students in the seventh grade.
Step-by-step explanation:
Let us assume that there are x number of students in the seventh grade.
Now, 3/8 of the seventh grade students were taking Advanced math at the beginning of the year, but seven dropped out by the end of the year.
So, after the end of the year there were
number of students taking advanced math.
So, as per given condition, 
⇒ 
⇒ x = 392
Therefore, there are 392 students in the seventh grade. (Answer)