Suppose that the commuting time on a particular train is uniformly distributed between 40 and 50 minutes. Bold a. What is the probability that the commuting time will be less than 43 minutes? Bold b. What is the probability that the commuting time will be between 42 and 48 minutes? Bold c. What is the probability that the commuting time will be greater than 48 minutes? Bold d. What are the mean and standard deviation of the commuting time?

a. 0.30

b. 0.60

c. 0.20

d. Mean = 45,  Standard Deviation = 2.8867

Step-by-step explanation:

a = 40, b = 50

a. What is the probability that the commuting time will be less than 43 minutes? Bold

P(X<43) = (43-40)/(50-40) = 0.30

b. What is the probability that the commuting time will be between 42 and 48 minutes? Bold

P(42<X<48) = (48-42)/(50-40) = 0.60

c. What is the probability that the commuting time will be greater than 48 minutes? Bold

P(X>48) = (50-48)/(50-40) = 0.20

d. What are the mean and standard deviation of the commutingtime?

1) Mean = (b+a)/2 = (40+50)/2= 45

2)SD =

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