Overview
The following 10 items are based on the following summarized research:
(*you will need your z-tables from Howell to complete many of these questions)
A psychologist studied self-esteem scores and found the sample data set to be normally distributed with a mean of 50 and a standard deviation of 5.
Part A**What raw score cuts off the bottom 10.03% of this distribution? Or to phrase another way, what raw score is associated with the 10.03 percentile?
Steps: (IT HELPS TO DRAW A GRAPH AND SHADE THE AREA(S) IN QUESTION)
To avoid mis-scoring by Blackboard, enter only numbers and, if required, negative signs (-) and decimal points (.).
What is the z-score that cuts off the bottom 10.03% of this distribution? Or to phrase another way, what z-score is associated with the 10.03 percentile? (HINT: Don't forget that z scores BELOW the mean are negative!)
What is the raw score that cuts off the bottom 10.03% of this distribution? Or to phrase another way, what raw score is associated with the 10.03 percentile?
Part B**What percentage of the scores is between 57.5 and 65?
Steps:
What is the z-score that corresponds to the raw score of 57.5?
What is the z-score that corresponds to the raw score of 65?
What percentage of the scores is between 57.5 and 65?
Part C:**A raw score of 35 is associated with what percentile?
Steps:
What is the z-score associated with a raw score of 35?
A raw score of 35 is associated with what percentile?
Part D:**What raw scores mark the middle 34% of this distribution? (HINT: DRAW AND SHADE IN THE MIDDLE 34% TO VISUALIZE! Remember.....the middle 34% means that 17% is BELOW the mean and 17% is ABOVE the mean......)
Steps:
What are the z-scores that mark the middle 34% of this distribution? The z-score below the mean is The z-score above the mean is What is the raw score below the mean?
A nurse studied PSA readings and found the sample data set to be normally distributed with a mean of 87 and a standard deviation of 7.25. What is the median of this distribution?
(Hint: this question has to do with knowing the characteristics of a normal distribution and where the mean, mode, and median lie in relation to one another in such a distribution. Check out the "Skewed and Normal Distributions" document under the Module 4 Instruction Materials.)
The following 9 questions (Q3 to Q11) are primarily conceptual questions based on Modules 3 and 4
In a negatively skewed distribution, Alisha scored the mean, Ken scored the median, and Catherine scored the mode. Who had the highest score?
Alisha | ||
Ken | ||
Catherine | ||
All three scored approximately the same |
In a normal distribution, Alisha scored the mean, Ken scored the median, and Catherine scored the mode. Who had the lowest score?
Alisha | ||
Ken | ||
Catherine | ||
All three scored approximately the same |
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The standard normal distribution has a mean of ___ and a variance of ____
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0; 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||
On a comprehensive final exam, the mean of the class exam scores was 517, and the standard deviation of the scores was 6. One particular student's z-score was 3. What was this student's raw score? The standard deviation for the sample consisting of 26, 48, and 70 is A medical association randomly selected 10 trauma surgeons and 10 medical researchers and asked them how flexible their schedule is on a 1 (not at all flexible) to 9 (very flexible) scale. The data are summarized below:
Select the statement that accurately reflects these results: (Hint: For this problem, the key is in the variance and in knowing what the variance represents! No calculations are necessary.)
A sample of data has a standard deviation of 35. If you were to multiply all of the scores in the data set by factor (or constant) of 1, what would the new standard deviation be? (Hint: The "Working with Constants in Equations" document under Instruction Materials will be helpful to you in answering this question.) Select the statement that is false.
Along with the mean, which of the following completely characterizes a standard normal distribution? (Hint: Refer to page 1 of the Module 4 course notes as well as section 6.2 of Howell, 7th edition, and section 8.3 of Utts, 3rd edition.)
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