Statistics and Probability Answers

The probability of a man hitting a target is 1/4. He fires 6 times. Find the probability that he hits the target at least once.

An electrical firm manufactures light bulbs that have a length of life that is normally distributed with mean equal to 778 hours and a standard deviation of 43 hours. Find the probability that a bulb burns between 755 and 892 hours.

In this class of 35 students, the following grade distribution was found. Construct a histogram, frequency polygon, and ogive for the data. (A = 4, B=3, C=2, D=1, F=0) (The following data in this exercise will be used for exercise 2-35).

There are 20 machines in a large plant. The machines operate independently of one another, breakdowns occur at random. The probability of a breakdown for each machine in one day’s operation is 0.10. Find the probability that exactly 4 breakdowns occur in one day

Suppose a fire broke out and you are trapped at your home. You send out three messages 

for help. An SMS at your friend’s mobile phone that has the probability of 0.1 of being 

seen; a message wrapped in a stone and thrown outside that has the probability 0.2 of being 

found; and a shout for help that has probability 0.3 of being heard. Find the probability that 

you are saved, assuming that the three ways are independent.

There are 10,000 sacks of rice. How many sacks of rice must be distributed to town A, B, and C if Town A has 15,000 families, Town B has 12,000, and Town C has 7,000?

Find the probabilities on a standard normal curve P(z<0.45)

A researcher gathers a sample of 49 police departments, finds out how many officers were fired for misconduct in each department over a 2-year time span, and plots each department’s score. From the list below, select the type of distribution that this researcher has created.

recall how to determine the values of the random variable by answering the given problem. Find the values of the ramdon variable Y representing the number of green balls when 2 balls are drawn in succession without replacement from a jar 4 red balls and 5 green balls

For the standard normal distribution, find the area between -1.55 and 1.90.