Recent Question/Assignment

*1 Paints possible: 1. Total attempts: 1
If A' represents a random variable coming from a normal distribution with m P(A' 6.7) = 0.37, then P(5 X 6.7) - 0.13.
|O True
O False
#2 Points possible: 1. Total attempts: 1
IfX represents a random variable coming from a normal distribution and P{X then P(X 11) = 0.36 .
0 True
O False
#3 Points possible: 1. Total attempts: 3
Which of the following statements are TRUE about the normal distribution? Check all that apply.
Cr ^The Empirical Rule only applies when a value is exactly 1, 2, or 3 standard deviations away from the mean.
/-* A data value with z-score = -1.5 is located 1-5 standard deviations below the mean.
LJ The mean corresponds to the z-score of 1. ¦
A z-score is the number of standard deviations a specific data value is from the mean of the distribution. j
ip The area to the left of a z-score plus the area to the right of that same z-score will always equal 1.
I
T
Points possible: L Total attempts: 1
If a distribution is normal with mean 12 and standard deviation 2. then die median is also 12.
OTrue
O False
#5 Points possible: 1. Total attempts: 3
In an Algebra class, the scores on a test are normally distributed. The middle 68% of the scores fall between 67 and 83. What are the mean and standard deviation Ibr this data?
Standard Normal Curve|
Mean:____________
Standard Deviation:
#6 Points possible: 1. Total attempts: 3
A set of exam scores is normally distributed with a mean = 82 and standard deviation ~ 9.
Use the Empirical Rule to answer the following questions.
95% of the data values lie between and .
% of the exam scores are less than or equal to 82.
¥ % of the exam scores are less than or equal to 73.
% of the exam scores are less than or equal to 100.
I
% of the exam scores are less than or equal to 91.
#7 Points possible: 1. Total attempts: 3
ft
A set of exam scores is normally distributed with a mean = 80 and standard deviation x 7. Use the Empirical Rule to complete the following sentences.
68% of the scores are between and
¦
95% of the scores are between and
99.7% of the scores are between unj
Points possible: 1. Total attempts: 3
In a normal distribution. a data value located 0.8 standard deviations below the mean has Standard Score: z *=
In a normal distribution. a data value located 2.4 standard deviations above the mean has Standard Score: z «
in a normal distribution, the mean has Standard Score: z = _______
#9 Points possible: 1. Total attempts: 3
Malik and Julio began arguing about who did better on their tests, but they couldn't decide who did better given that they took different tests. Malik took a test in Social Studies and earned a 71, and Julio took a test in English and earned a 66.2. Use the fact that all the students' test grades in the Social Studies class had a mean of 73.2 and a standard deviation of 9.3, and all the students' test grades in English had a mean of 64.2 and a standard deviation of 8.6 to answer the following questions.
a) Calculate the z-score for Malik's test grade.
z = [Round your answer to two decimal places.]
b) Calculate the z-score for Julio's test grade.
z = [Round your answer to two decimal places.]
c) Which person did relatively better?
O Malik
O Julio |
O They did equally well.
£10 Pu«»u possible: 1. Total attempts: 3
The picture below has 3 normal curves plotted on the same set of axes.
4a«u UfttMia v* M*Jto # /« **** »*-.*.
Compare the standard deviations of the 3 distributions. Explain your reasoning.
O 7he three distributions all have the same mean because each curve has the same center and me three distributions have the same standard deviation because die ursumu: iruu each graph's mean to the transition point or mfleriicm rwint is the same for each distribution
O The three distributions have different values for the mean because each curve has a atffvrem center; but, on the other hand, the three distributions have the same standard deviation because the distance from each graph's mean to the transition point or inflection point is the same for each distribution,
O The three distributions have different values for the mean because each curve has a different center and the three distributions have different standard deviations because the distance from each graph's mean to the transition point or inflection point is different for each distribution.
O The three distributions all have the same mean because each curve has the same center; but on the other hand, the three distributions have different standard deviations because the distance from each graph's mean to the transition point or inflection point is different for each distribution.