Question
please help me solve these.. having trouble?
l AttpalmyCourses utrgv.edu/webapps/assessment/take/launch.jsp?course assessment id 191804-1&course; id .45012 ew attempt 18contentid 2591667-18step a niversity of Remaining Time: 45 minutes, 42 seconds. oustion Completion status My Courses QUESTION 5 5 points save Answer The average price of an electric tooth brush is s5.25 with a standard deviation of s1.25 Using Chebyshev's theorem, nd the price range for which at least 55.56% of the es will sell $3.25 to $7.25 S3.53 to S13.28 $3.38 to $7.13 $2.52 to $8.50 QUESTION 6 5 points Save Answer The average price of an electric tooth-brush is S12 with a standard deviation of S1.25. Find the price range for hich approximately 68% ofthe tooth-brushes wll sell. Use the Empirical (Normal) Rule) $10.50 to $14.50 $950 to $13.25 O $9.25 to $14.25 O $10.75 to S13.25 5 points QUESTION 7 In a statistics course the average final exam score is 78 with a standard deviation of2.Find the z-score for a test score of88. 02 5 points Answer QUESTION 8 score of2.3 In a statistics course the average final exam score is 84 with a standard deviation of 5 Find the test score that corresponds to a 85.2 95.5 72.5 9-00 PM
Explanation / Answer
(5) 1 - (1/k^2) = 1 - 0.5556 = 0.4444
k = 1.5
x1 = 5.25 - 1.5(1.25) = 3.375 and x2 = 5.25 + 1.5(1.25) = 7.125
Option C
(6) 68% corresponds to ± 1 standard deviation of the mean
x1 = 12 - 1.25 = 10.75 and x2 = 12 + 1.25 = 13.25
Option D
(7) z = (88 - 78)/2 = 5
Option B
(8) x = + z * = 84 + 2.3(5) = 95.5
Option C.
