Statistics and Probability Answers

Use the fact that the mean of a geometric distribution is μ = 1/p and the variance is σ2 = q/p2.
A company assumes that 0.5% of the paychecks for a year were calculated incorrectly. The company has 200 employees that examines the payroll records from one month.
1. Find the mean, variance, and standard deviation.
2. How many employees payroll records would you expect to examine before finding one with an error?

It is noted that 8% of kaplan students are left handed if 20 (TWENTY) students are randomly selected, calculate the
1) probability that none of them are left-handed
2) probability that at most 2 are left handed,
3) standard deviation for the number of left-handed student
4)if 50 classes of 20 students are randomly selected,what is the 10 classes have no left handed students?

Can i get the Question 4?

Thank you very much

If 50 (FIFT) classes of 20 (TWENTY) students are randomly selected, what is the probability that 10 (TEN) classes have no left-handed students

A pain reliever currently being used in a hospital is known to bring relief to patients in a mean time of 3.5minutes. To compare a new pain reliever with the one currently in use, the new drug is administered to a random sample of fifty patients’. The mean time to relief for the sample of patients is 2.8minutes and the variance is 1.3minutes.Do the data provide sufficient evidence to conclude that the new drug was effective in reducing the mean time until a patient receives relief from pain?. Test using p-value and let =0.10

1. A certain shop repairs both audio and video components. Let A denote the event that the next component brought in for repair is an audio component, and let B be the event that the next component is a compact disc player (so the event B is contained in A). Suppose that P(A)= 0.6 and P(B) =0.05. What is P(B|A)?

2.Each of 12 refrigerators of a certain type has been returned to a distributor because of an audible, high-pitched, oscillating noise when the refrigerator is running. Suppose that 7 of these refrigerator have defective compressor and the other 5 have less serious problems. If the refrigerators are examined in random order. Let X be the number among the first 6 examined that have a defective compressor. What is the probability that X exceeds its mean value by more than 1 standard deviation?

3. Evaluate (x-2)!(y-4) if x=6 and y=9

Fit a normal curve to the following data
x: 2 4 6 8 10
f: 1 4 6 4 1

How many 3 digits numbers greater than 300 can be formed using the digits 1, 2, 3, 4, 5 if no digit can be repeated and the first digit cannot be 3?

A coin is rolled thrice, what is the probability for an event that at least two head or at least two tails occur?
(7/3)

Two petrol stations are located in a street at Victoria island, each of the petrol stations has 5 pumps, an experiment was carry out to determine the number of pumps in use at a particular time of the day at each of the petrol stations, assume an experimental outcome is (x,y), where x specified the number of pumps in use at the 1st station and y the number of pumps in use at the second station. How many of such outcome will you have in this experiment?

A bus starts with 6 people and stops at 10 different stops, how many different ways can the 6 people depart if any passenger can depart at any bus stop ____