Statistics and Probability Answers

1. What measure of central value best estimates the population mean?
2. Why is the interval estimate a preferred value for the population parameter?
3. Which of the following illustrates confidence level?

a. 95%

b. 12.5

c. 50.0

d. 90 - 95

PROBABILITY AND STATISTICS

Question 3 The average lifespan of a Ghanaian is 57years. The average lifespan of males in Ghana is known to be 55 years while the average lifespan of females in Ghana is known to be 60 years. The average lifespan of people from the Northern region of Ghana is known to be 58 years while the average lifespan of people in the East region of Ghana is known to be 54 years. Use the above information to answer the following questions:

(i).With your reasons, discuss all possible population parameters from the above information.

(ii).With your reasons, discuss all possible sample statistics from the above information.

(iii) Compare and contrast the average lifespan of males and females. Which group average is more likely to represent the corresponding population parameter?

Give reasons for your answer.

What salary would an employee make that is three standard deviations above the mean and three standard deviations below the mean?

answer for If the median mass of five chemical reagent bags in the store room is 6.5 kg and one further 7 kg bag of chemical reagent is added to the consignment, then: (a) the new median mass will be about 6.6 kg (b) the median will increase (c) it is impossible for the new median mass to be less than it was (d) it is impossible

A meeting of envoys was attended by 4 Koreans and 2 Filipinos. If three envoys were selected at random one after the other, determine the values of the random variable K representing the number of Koreans.

1. The probability that a cellular phone company kiosk sells X number of new phone  contracts per day is shown below. Find the mean, variance, and standard deviation for  this probability distribution.  

X - 7 8 9 12 14 

P (X) - 0.4 0.3 0.15 0.1 0.05 

What is the probability that they will sell 9 or more contracts three days in a row?

2. A pizza shop owner determines the number of pizzas that are delivered each day. Find  the mean, variance, and standard deviation for the distribution shown. If the manager  stated that 23 pizzas were delivered on one day, do you think that this is a believable  claim?  

Number of pizzas  X - 12 18 15 13 20 

Probability  P(X) - 0.1 0.2 0.3 0.3 0.1

The mean weight of 500 college students is 70 kg and the standard deviation is 5 kg

Assuming that the weight is normally distributed, determine how many students weights:

a: Between 60 kg and 75 kg

b. More Than 90 kg

c. less than 65 kg

An elevator in the hospital has a weight limit of 1650 pounds. Suppose an average weight of

the people who use this elevator is 140 pounds with a standard deviation of 25 pounds.

Assuming that the distribution of weights is approximately normal and a random sample of

11 people are selected, what is the probability that the random sample will exceed the weight

limit?

The formula we are given is z=x̄-μ/(σ/√n)

using the multinomial distribution formula, if X sub 1 is 3 what is P sub 1?

In a study of distances traveled by buses before the first major engine failure, a sample of 191 buses resulted in a mean of 96,700 miles and a standard deviation of 37,500 miles. At the 0.05 level of signıficance, test the manufacturer's claim that the mean distance traveled before a major engine failure is more than 90,000 miles.

1. Claim:

Ho:

Ha:

2. Level of Significance:

Test- statistic:

Tails in Distribution:

3. Reject Ho if:

4. Compute for the value of the test statistics.

5. Make a decision:

6. State the conclusion in terms of the original problem.