Mat 540 Quiz 4
Quiz 2
Chapters 4 & 5__TEAM A week 5________________________
1) Use the standard normal distribution to find P(-2.25 < z < 1.25).
A) .0122 B) .8821 C) .8944 D) .4878
P(-2.25 < z < 1.25) = F(1.25) - (1 - F(2.25)) = 0.89435 - (1 - 0.987776) = 0.882126
2) Before a new phone system was installed, the amount a company spent on personal calls followed a normal distribution with an average of $ 900 per month and a standard deviation of $50 per month. Refer to such expenses as PCE's (personal call expenses). Using the distribution above,
a. what is the probability that during a randomly selected month PCE's were between $775.00 and $990.00?
A) .0421 B) .0001 C) .9999 D) .9579
b. what is the probability that during a randomly selected month PCE's …show more content…
What is the probability that at the time the machine is checked it is pumping more than 9.0 gallons per minute?
A) .7692 B) .25 C) .50 D) .875
c. What is the probability that at the time the machine is checked it is pumping between 9.5and 10.5 gallons per minute?
A) .50 B) 667 C) .7692 D) .25
5) The time between customer arrivals at a furniture store has an approximate exponential distribution with mean θ = 8.5 minutes.
a. If a customer just arrived, find the probability that the next customer will arrive in the next 5 minutes.
A) .817316 B) .182684 C) .555306 D) .444694
b. .If a customer just arrived, find the probability that the next customer will arrive in the next 3 minutes.
A) .555306 B) .297381 C) .444694 D) .702618
6) The director of a hospital wishes to estimate the mean number of people who are admitted to the emergency room during a [pic] period. The director randomly selects 100 different [pic] periods and determines the number of admissions for each. For this sample, [pic] and [pic] Estimate the mean number of admissions per [pic] period with a 99% confidence interval.
A) 16.3 ± 4.120 B) 16.3 ± 1.030 +C) 16.3 ± . 10.3 D) 16.3 ± .
Chapters 4 & 5__TEAM A week 5________________________
1) Use the standard normal distribution to find P(-2.25 < z < 1.25).
A) .0122 B) .8821 C) .8944 D) .4878
P(-2.25 < z < 1.25) = F(1.25) - (1 - F(2.25)) = 0.89435 - (1 - 0.987776) = 0.882126
2) Before a new phone system was installed, the amount a company spent on personal calls followed a normal distribution with an average of $ 900 per month and a standard deviation of $50 per month. Refer to such expenses as PCE's (personal call expenses). Using the distribution above,
a. what is the probability that during a randomly selected month PCE's were between $775.00 and $990.00?
A) .0421 B) .0001 C) .9999 D) .9579
b. what is the probability that during a randomly selected month PCE's …show more content…
What is the probability that at the time the machine is checked it is pumping more than 9.0 gallons per minute?
A) .7692 B) .25 C) .50 D) .875
c. What is the probability that at the time the machine is checked it is pumping between 9.5and 10.5 gallons per minute?
A) .50 B) 667 C) .7692 D) .25
5) The time between customer arrivals at a furniture store has an approximate exponential distribution with mean θ = 8.5 minutes.
a. If a customer just arrived, find the probability that the next customer will arrive in the next 5 minutes.
A) .817316 B) .182684 C) .555306 D) .444694
b. .If a customer just arrived, find the probability that the next customer will arrive in the next 3 minutes.
A) .555306 B) .297381 C) .444694 D) .702618
6) The director of a hospital wishes to estimate the mean number of people who are admitted to the emergency room during a [pic] period. The director randomly selects 100 different [pic] periods and determines the number of admissions for each. For this sample, [pic] and [pic] Estimate the mean number of admissions per [pic] period with a 99% confidence interval.
A) 16.3 ± 4.120 B) 16.3 ± 1.030 +C) 16.3 ± . 10.3 D) 16.3 ± .