# Question: For a large Internet service provider ISP web virus attacks

For a large Internet service provider (ISP), web virus attacks occur at a mean rate of 150 per day.

(a) Estimate the probability of at least 175 attacks in a given day.

(b) Estimate the probability of fewer than 125 attacks.

(c) Is the normal approximation justified? Show all calculations.

(d) Use Excel to calculate the actual Poisson probabilities. How close were your approximations?

(a) Estimate the probability of at least 175 attacks in a given day.

(b) Estimate the probability of fewer than 125 attacks.

(c) Is the normal approximation justified? Show all calculations.

(d) Use Excel to calculate the actual Poisson probabilities. How close were your approximations?

**View Solution:**## Answer to relevant Questions

In Santa Theresa, false alarms are received at the downtown re station at a mean rate of 0.3 per day. (a) What is the probability that more than 7 days will pass before the next false alarm arrives? (b) Less than 2 days? (c) ...The time it takes a ski patroller to respond to an accident call has an exponential distribution with an average equal to 5 minutes. (a) In what time will 90 percent of all ski accident calls be responded to? (b) If the ski ...Suppose that the distribution of oil prices ($/bbl) is forecast to be T(50, 65, 105). (a) Find the mean. (b) Find the standard deviation. (c) Find the probability that the price will be greater than $75. (d) Sketch the ...The weekly demand for Baked Lay's potato chips at a certain Subway sandwich shop is a random variable with mean 450 and standard deviation 80. Find the value(s) of X for each event. Show your work. a. Highest 50 percent b. ...Procyon Manufacturing produces tennis balls. Their manufacturing process has a mean ball weight of 2.035 ounces with a standard deviation of 0.03 ounce. Regulation tennis balls are required to have a weight between 1.975 ...Post your question