Step-by-step explaA bag of marbles contains only purple and yellow marbles. The bag has three times as many yellow marbles as purple. The bag contains 164 total marbles. Write an equation or system of equations to find out how many of each color of marble is in the bag. Define your variable(s) and expressions. Show how you checked your answer.

2nation:

7 0

3 years ago

A large stockpile of used pumps contains 20% that are currently unusable and need to be repaired. A repairman is sent to the sto

Scrat [10]

Answer:

Expected value = 190

Variance = 4000

Step-by-step explanation:

Let X be the number of the trials until the third success of the bad pump.

This implies that X is a negative binomial distribution having θ = 20% = 0.2.

Now, if for example it will take X trials to use up the three pumps, then the total time is 10 min/trials + extra 10 minutes for the 3 bad pumps

This means the total time is written as;

T = 10X + (10 + 10 + 20)

T = 10X + 40

Mean which is also expected value of X is;

μ_x = 3/0.2 = 15

Variance of X is; σ²_x = 40

Thus;

Mean of T will be;

μ_T = 10μ_x + 40

μ_T = 10(15) + 40

μ_T = 190

Also, variance of T will be;

σ²_T = 10²•σ²_x

σ²_T = 100 × 40

σ²_T = 4000

7 0

3 years ago