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Please help me answer theses. Thank you
on me stuaernts resuits neau trie steps Deiow ald compiete each item. Suppose a professor gives an exam to a class of 40 students and the scores are as follows. (Open the Lab 7.2 data set in StatCrunch.) 1. 35 44 46 4747 48 49 51 53 54 55 55 57 57 57 58 59 5959 59 60 60 60 60 60 62 62 62 6468 69 7072 73 7375 75 77 82 88 a. Find each of the following: i. Mean: ii. Median: ii. Standard deviation iv. Z-score for a student who originally scored 54 on the exam: b. Create a histogram of the scores and comment on the shape of the distribution. (Use a separate page if necessary.) Suppose the professor decides to adjust scores by adding 25 points to each students score. Add 25 to each score. (Data>Compute>Expression>Build>Build the expression: Scores +25>Okay>Compute!) This data set is in the column Score + 25 of the data set. 2. a. Find the following after the adjustment: i. Mean: ii. Median: ii. Standard deviation: iv. Z-score for a student who originally scored 54 on the exam: b. Create a histogram of the scores (starting point: 55 and bin size: 10) and comment on the shape of the distribution. (Put it next to the first one you created.) Fundamentals of Statistics by Sullivan, III, Se
Suppose the professor wants the final scores to have a mean of 75 and a standard deviation of 8. To find a students new score, first calculate their z-score and then use the z-score along with the new mean and standard deviation to find their adjusted score. Use StatCrunch to find the adjusted score for each student. 3. Finding Z-score: Data Compute>Expression Build Build the expression: (Original Scores-mean(Original Scores])/std( Original Scores):> Okay Compute!) test score- mean Z-Score standard deviation New column, (Original Scores - mean(Original Scores))/std(Original Scores), added to data table! Rename this column as Z-score. Adjusted test score Finding Adjusted test icore Data>Compute> Expression Build> Build the expression: Z- score 8+75> Okay Compute!) Z-Score standard deviation + mean New column, Z-score added to data table! 8+75, Rename this column as Adjusted Scores a. Create a histogram of the Adjusted scores (starting point: 50 and bin size: 10) and and compare it to the histogram created in #1
Verify that the mean of the adjusted test scores is 75 and the standard deviation is 8. b. Fundamentals of Statistics by Sullivan, Il1,Se Suppose the professor wants the scores to be curved in a way that results in the following: 4. Top 10% of scores receive an A Bottom 10% of scores receive an F Scores between the 70th and 90th percentile receive a B Scores between the 30th and 70th percentile receive a C Scores between the 10th and 30th percentile receive a D Find the range of scores that would qualify for each grade under this plan. (Use the normal calculator and the mean of 60.53 and standard deviation of 10.96.) Exam Scores Letter Grade s. Which of the three curving schemes seems the fairest to you? First, think about your answer. Then pair up with someone near you and explain your response to the question. Finally, share your ideas with the group
math   Statistics-And-Probability   
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Answer #1

Q1. I am using R.

> yく4(35,44,46,47,47,48,49, 51,53,54 , 55,55,57,57,57 , 58,59,59,59,59,60,60,60, 60,60,62, 62,62 , 64,68,69,70,72,73,73,75,75,77,82,88) > mean(y) [1] 60.525 medianCy) [1] 59. 5 sd(y) [1] 10.95676 > z=(54-mean(y))/sd(y) > Z [1] -0. 5955226 > hist(y)Histogram ofv 30 40 50 60 70 80 90

Shape = Bell Shaped

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