Purchase Solution

Calculating Probabilities Assuming Normal Distribution

Not what you're looking for?

Ask Custom Question

For the following answer True or False for each question
1. A population forms a normal distribution with µ=80 and ơ=10. In this population, 69.15% of the scores greater than x=75.
2. A population forms a normal distribution with µ=80 and ơ=10. In this population, 84.13% of the scores greater than x=90.
3. A population forms a normal distribution with µ=80 and ơ=10. In this population, 42.07% of the scores greater than x=78.
4. If one score is randomly selected from a normal distribution with µ=100 and ơ=20, the probability of obtaining a score greater than x=110 is 0.6915.
5. If one score is randomly selected from a normal distribution with µ=100 and ơ=20, the probability of obtaining a score less than x=95 is 0.4013.
6. If one score is randomly selected from a normal distribution with µ=100 and ơ=20, the probability of obtaining a score less than x=70 is 0.0013.
7. If one score is randomly selected from a normal distribution with µ=100 and ơ=20, the probability of obtaining a score between x=90 and x=100 is 0.3085.
8. If one score is randomly selected from a normal distribution with µ=100 and ơ=20, the probability of obtaining a score between x=80 and x=120 is 0.3413.
9. A vertical line drawn through a normal distribution at z=-0.75 will separate the distribution into two sections. The proportion in the smaller section is 0.2734.
10. If samples of size n=16 are selected from a population with µ=40 and ơ=8, the distribution of sample means will have an expected value of 40.
11. If samples of size n=16 are selected from a population with µ=40 and ơ=8, the distribution of sample means will have a standard error of 2 points.
12. The mean for a sample of n=4 scores has a standard error of 5 points. This sample was selected from a population with a standard deviation of ơ=20.
13. The mean for a sample of n=16 scores has an expected value of 50. This sample was selected from a population with a mean of µ=50.
14. On average, a sample of n=16 scores from a population with ơ=10 will provide a better estimate of the population mean than you would get with a sample of n=16 scores from a population with ơ=5.

Purchase this Solution

Solution Summary

The solution gives detailed steps on answerting 14 short questions regarding on probability calculation assuming the normal distribution. All questions are explained in details.

Solution Preview

1. A population forms a normal distribution with µ=80 and ơ=10. In this population, 69.15% of the scores greater than x=75.
P(X>75)=P(Z>(75-80)/10)=P(Z>-0.5)=69.15%. True

2. A population forms a normal distribution with µ=80 and ơ=10. In this population, 84.13% of the scores greater than x=90.
P(X>90)=P(Z>(90-80)/10)=P(Z>1)=15.87%. False

3. A population forms a normal distribution with µ=80 and ơ=10. In this population, 42.07% of the scores greater than x=78.
P(X>78)=P(Z>(78-80)/10)=P(Z>-0.2)=57.93%. False

4. If one score is randomly selected from a normal distribution with µ=100 and ơ=20, the probability of obtaining a score greater than x=110 is 0.6915. ...

Purchase this Solution


Free BrainMass Quizzes
Know Your Linear Equations

Each question is a choice-summary multiple choice question that will present you with a linear equation and then make 4 statements about that equation. You must determine which of the 4 statements are true (if any) in regards to the equation.

Geometry - Real Life Application Problems

Understanding of how geometry applies to in real-world contexts

Solving quadratic inequalities

This quiz test you on how well you are familiar with solving quadratic inequalities.

Probability Quiz

Some questions on probability

Graphs and Functions

This quiz helps you easily identify a function and test your understanding of ranges, domains , function inverses and transformations.