Answer: d. np(1 - p).
Step-by-step explanation:
Let x be any binomial variable which represents the number of success such that
, where n is the sample size or the total number of trials and p is the probability of getting success in each trial .
Then, the mean E(x) and the variance Var(x) for the binomial distribution is given by equation :


where n is the sample size or the total number of trials and p is the probability of getting success in each trial .
Therefore , the correct option is option d. np(1 - p) .
Answer
x=3 or (3,0) and if you need it y=-2x+3
Step-by-step explanation:
I'm not very good at explaining things, sorry
1. Let hardcover books = X
Paperback books would be 4x -3 ( 3 less than 4 times)
Now you have:
X + 4x-3 = 447
Simplify:
5x - 3 = 447
Add 3 to each side:
5x = 450
Divide both sides by 5:
x = 450/5
x = 90
He has 90 hardcover books.
2. 300 miles / 25 miles per gallon = 12 gallons of gas.
12 gallons x $$ per gallon = $48 dollars
3. Subtract base pay from total:
1916 - 800 = 1,116 worth of commissions.
Divide commissions by percentage:
1116 / 0.09 = $12,400 total sales.
4.
Find the median of the heights: 65-50 = 15. 15/2 = 7.5
Median = 50+7.5 = 57.5
The equation would be |h-57.5| < 7.5