Term
| What is a Continuous Random Variable? |
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Definition
| It has infinitely many values, and those values are often associated with measurements on a continous scale with no gaps or interruptions. |
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Term
| What is Normal Distribution |
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Definition
| bell-shaped and syymetric probability distribution described algebraically by formula 6-1 on page 246. |
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Term
| what are the 3 properties of a Normal Distribution |
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Definition
1) it is bell-shaped
2) it has a mean equal to 0
3) it has a standard deviation equal to 1 |
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Term
| what is a Uniform Distribution? |
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Definition
prob. distribution in which every value of the random variable is equally likely;
the graph is a rectangle in shape;
it's values are spread evenly over the range of possibilites |
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Term
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Definition
| A graph of a continuous prob. distribution. |
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Term
| What are the 2 properties of a Density Curve |
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Definition
1)the total area under the curve must equal 1
2) every point on the curve must have a vertical height that is 0 or greater. |
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Term
| For review, what is a Parameter? |
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Definition
| A numerical measurement describing some characteristic of a population. |
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Term
| What is the Standard Normal Distribution |
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Definition
Normal distribution with a mean of 0 and a standard deviation equal to 1.
The total area under its density curve is equal to 1. |
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Term
| What is the z score in regards to a graph for a standard normal distribution? |
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Definition
| it is the distance along the horizontal scale of the standard normal distribution |
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Term
| What is the Area in regards to a graph of a standard normal distribution? |
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Definition
| The Region under the curve |
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Term
| What do you do to find a negative z score that is pertaining to a number from the right? |
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Definition
| By using the Tables in the Appendix, once you have found the correct probability that applies to your negative number, subtract it from 1...this is because the area must equal 1. |
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Term
| How do you find the area corresponding to a specific region in between two z scores? |
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Definition
Once the values are found from the Appendix, find the difference between the two areas.
ex. Find the probability that a thermometer will read between -2.00 and 1.50.
From the Appendix, we know that -2.00 = 0.0228 and 1.50 = 0.9332, so find the difference...
0.9332 - 0.0228 = 0.9104. |
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Term
| What is the procedure for finding a z score from an already known area? |
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Definition
1) Draw a bell shaped curve and identify the region under the curve that corresponds the given prob.
2) Work from the side that you have corresponding given information(left or right)
3)Using the cumulative area from the left, locate the closest prob. in the body of the Appendix and identify the proper z score. |
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Term
| What do you do when a desired value is midway between 2 table values? |
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Definition
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Term
| What should you do if normal standard parameters are not used, such as μ=0 and σ=1? |
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Definition
Use the following formula to convert the undesired values into ones that match up with a normal standard distribution (and round z scores to 2 decimal places).
z = x - μ
σ |
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Term
| What are the procedures for finding areas with nonstandard normal distributions? |
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Definition
1) Sketch a normal curve,
2) label mean and specific values,
3) shade desired region,
4) use the conversion formula to convert nonstandard into standard values for the appropriate z score,
5) Refer to Appendix A for the area values |
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Term
| How to solve for x with a nonstandard normal distribution |
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Definition
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