A California water company has determined that the average customer billing is $1,250 per year and the amounts billed have an exponential distribution. a. What is the mean and lamda? b. Calculate the probability that a random chosen customer would spend more than $5,000 c. Compute the probability that a random chosen customer would spend more than the average amount spent by all customers of this company.

a)

Mean

b)

c)

Step-by-step explanation:

From the given information:

a.)

Mean

Let consider X to be a random variable that follows an exponential distribution; then:

P(X) = 1 -   since

b.)

The required probability that a random chosen customer would spend more than $5,000 can be computed as:

c.)

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500