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Description
Flashcards by jennabarnes12387, updated more than 1 year ago
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Created by jennabarnes12387
over 10 years ago
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| Question | Answer |
| if a school has a GPA of 2.8 and a standard deviation of 0.8 what percent of students have a GPA less then 2? greater then 3? | P(x< or equal to 2) = P(Z < -1) = 0.1587 P(x>3) = P(Z>0.25)=1-P(X< of equal to 0.25) = 1-0.5987 = 0.4013 |
| between 2 and 3? | - P(2<x<3) = P(-1<Z<0.25)P(Z < 0.25) – P(Z<-1)0.5987 – 0.1587 = 0.4400 |
| What is the minimum GPA needed to be in the top 10% | creates two areas, 0.1, and 0.9. find the Z score for 0.9 which is 1.28 and then use to solve for x in the equation Z = x-u/sigma |
| what is a normal probability plot? | a scatter plot of the normal Z score pairs |
| how do you find the Z score pairs? | order the data from smallest to largest. then us table 3 to find the normal sores using the z scores. then plot the data (z,x) |
| the mean of X is always equal to____ no matter the width of the distribution? | x bar |
| what is parameter? | a number calculating a population and describes the characteristics of a population |
| what is a statistic? | a number calculated from and describing the characteristics of a sample |
| how do we find x bar? | u, sigma/ square root of n |
| the avergae adult weight is 175 pounds with a standard deviation of 25 pounds. an elevator has a weight limit of 10 people or 2000 pounds. What is the probability that the ten people who get on an elevator exceed the weight limit? | P(overload) = x1 + x2 + ………x10 > 2000 pounds = X1 + x2 + ……….. x10 / 2 = 2000/10 = 200. the Z score for 200 is 3.16. 1-p(z < or equal to 3.16) = 0.9992 = 0.0081-p(z < or equal to 3.16) = 0.9992 = 0.008 |
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