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1. In words, define a probability distribution? How does a frequency distributio

ID: 3328426 • Letter: 1

Question

1. In words, define a probability distribution? How does a frequency distribution differ from a probability distribution? (5 points) 2.A normal distribution has m = 80 and s = 10" For this distribution, find each of the following probability values. Explain the meaning of each number that you obtained (5 points). a) P(X> 90 b) P(X 65 c) P(X2 87) d) P(X 2115) e PX 50) 3. Define correlation (in words), give statistical formula. Explain the relationship between correlation and causation. When is it appropriate to use correlation to answer research questions? (5 points) 4. To evaluate the effectiveness of managerial styles a study was conducted where sales of employees managed by managers with managerial style 1 were compared to sales of employees managed by managers implementing style 2 Compute the correlation coefficient to compare the two managerial styles. Explain your findings. For your calculations consider the following datasets (10 points): Quarter 1 Quarter 2 Quarter 3 Quarter 4 $71 1 $100 535 561 $45 $71 $61 $65 $91 $34 $74 S79 $102

Explanation / Answer

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2.

Mean = 80, Sigma = 10. Using the params to normalize the R.V:

a. P(X>90) = P(Z> 90-80/10) = P(Z>1) = .1587
b. P(X<65) = P(Z<65-80/10) = P(Z<-1.5) = .0668
c. P(X>=87) = P(Z>=87-80/10) = P(Z>=.7) = 1-.7580 = .2420
d. P(X>=115) = P(Z>=115-80/10) = P(Z>=3.5)= 0.000233
e. P(X<=50) = P(Z<=50-80/10) = P(Z<=-3) = 0.00135