Question 1201542: A distribution of values is normal with a mean of 99.5 and a standard deviation of 16.
Find P71, which is the score separating the bottom 71% from the top 29%.
P71 =
Enter your answer as a number accurate to 1 decimal place. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.
The combined SAT scores for the students at a local high school are normally distributed with a mean of 1450 and a standard deviation of 307. The local college includes a minimum score of 2402 in its admission requirements.
What percentage of students from this school earn scores that fail to satisfy the admission requirement?
P(X < 2402) = %
Enter your answer as a percent accurate to 1 decimal place (do not enter the "%" sign). Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.
A study was conducted on students from a particular high school over the last 8 years. The following information was found regarding standardized tests used for college admitance. Scores on the SAT test are normally distributed with a mean of 1056 and a standard deviation of 205. Scores on the ACT test are normally distributed with a mean of 21.6 and a standard deviation of 4.6. It is assumed that the two tests measure the same aptitude, but use different scales.
If a student gets an SAT score that is the 54-percentile, find the actual SAT score.
SAT score =
Round answer to a whole number.
What would be the equivalent ACT score for this student?
ACT score =
Round answer to 1 decimal place.
If a student gets an SAT score of 1569, find the equivalent ACT score.
ACT score =
Round answer to 1 decimal place.
Major League Baseball now records information about every pitch thrown in every game of every season. Statistician Jim Albert compiled data about every pitch thrown by 20 starting pitchers during the 2009 MLB season. The data set included the type of pitch thrown (curveball, changeup, slider, etc.) as well as the speed of the ball as it left the pitcher’s hand. A histogram of speeds for all 30,740 four-seam fastballs thrown by these pitchers during the 2009 season is shown below, from which we can see that the speeds of these fastballs follow a Normal model with mean μ = 92.12 mph and a standard deviation of σ = 2.43 mph.
Compute the z-score of pitch with speed 87.4 mph. (Round your answer to two decimal places.)
Correct
Approximately what fraction of these four-seam fastballs would you expect to have speeds between 91.9 mph and 93.5 mph? (Express your answer as a decimal, not a percent, and round to three decimal places.)
Approximately what fraction of these four-seam fastballs would you expect to have speeds below 91.9 mph? (Express your answer as a decimal, not a percent, and round to three decimal places.)
A baseball fan wishes to identify the four-seam fastballs among the slowest 22% of all such pitches. Below what speed must a four-seam fastball be in order to be included in the slowest 22%? (Round your answer to the nearest 0.1 mph.)
mph
Scores for a common standardized college aptitude test are normally distributed with a mean of 501 and a standard deviation of 105. Randomly selected men are given a Test Preparation Course before taking this test. Assume, for sake of argument, that the preparation course has no effect.
If 1 of the men is randomly selected, find the probability that his score is at least 566.6.
P(X > 566.6) =
Enter your answer as a number accurate to 4 decimal places.
If 16 of the men are randomly selected, find the probability that their mean score is at least 566.6.
P(M > 566.6) =
Enter your answer as a number accurate to 4 decimal places.
The physical plant at the main campus of a large state university recieves daily requests to replace florecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 64 and a standard deviation of 11. Using the empirical rule (as presented in the book), what is the approximate percentage of lightbulb replacement requests numbering between 64 and 75?
ans = %
A company has a policy of retiring company cars; this policy looks at number of miles driven, purpose of trips, style of car and other features. The distribution of the number of months in service for the fleet of cars is bell-shaped and has a mean of 53 months and a standard deviation of 10 months. Using the empirical rule (as presented in the book), what is the approximate percentage of cars that remain in service between 23 and 43 months?
ans =
Answer by ikleyn(52778)   (Show Source):
You can put this solution on YOUR website! .
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