8719.2 is the answer ! Well sorry for not writing the method and stuff.
Answer:
The mean of X is 2
Step-by-step explanation:
Given the data in the question;
set of 10 cards consist of 5 red card and 5 blacks
cards are chosen, replaced and shuffled four times;
number of independent trials n = 4
now, since its is replaced, the probability of getting a red card in each trial will be;
p = 5/10 = 0.5
let X rep the number of red cards observed in the four trials.
the random variable follows binomial distribution where
n = 4 and p = 0.5
so
E(X) = ∑xP( X = x )
E(X) = np
we substitute
E(X) = 4 × 0.5
E(X) = 2
Therefore, The mean of X is 2
Answer: The selling price was $195,200
Step-by-step explanation:
Given:
Tax paid = $488
Rate = $1 per $400 = 1/400
Using the formula;
Tax = rate × selling price
Selling price = tax /rate
Selling price = $488/(1/400) = $488×400 = $195200
Answer:
$1210
Step-by-step explanation:
Let x be total amount
First John spent $110 on a radio and 4/11 of what was left on presents for his friends so he was left with
Then he put 2/5 of his remaining money into a checking account
Rest he donated to charity
Hence total amount of money John originally had was $1210
