Homework Answers
Solution:
Given: x = scores on certain intelligence test for children ages 13 and 15 years are approximately Normally distributed.
Mean =
Standard Deviation =
Part a) Find:
P( X > 83 ) =..........?
Find z score for x = 83
Thus we get:
P( X > 83 ) = P( Z> -0.86)
P( X > 83 ) = 1 - P( Z < -0.86)
Look in z table for z = -0.8 and 0.06 and find area.
P( Z < -0.86) = 0.1949
Thus
P( X > 83 ) = 1 - P( Z < -0.86)
P( X > 83 ) = 1 - 0.1949
P( X > 83 ) = 0.8051
Part b)
Find x value such that:
P( X < x ) = 20%
P( X < x ) = 0.2000
thus find z value such that:
P( Z < z) = 0.2000
Look in z table for Area = 0.2000 or its closest area and find z value.
Area 0.2005 is closest to 0.2000 and it corresponds to -0.8 and 0.04
thus z= -0.84
Now use following formula to find x value:
Part c)
Find x value such that:
P( X > x ) =10%
P( X > x ) = 0.1000
thus find z value such that:
P( Z > z) = 0.1000
that is find z value such that:
P( Z < z ) = 1 - P( Z > z )
P( Z < z ) = 1 - 0.1000
P( Z < z ) = 0.9000
Look in z table for area = 0.9000 or its closest area and find z value:
Area 0.8997 is closest to 0.9000 and it corresponds to 1.2 and 0.08
thus z = 1.28
Thus
Add Answer to:
Normal Distributions Homework: Problem 20 Previous Problem List Next (1 point) Scores on a certain intelligence...
(1 point) Scores on a certain intelligence test for children between ages 13 and 15 years...
(1 point) Scores on a certain intelligence test for children between ages 13 and 15 years are approximately normally distributed with 27 u= 106 and o (a) What proportion of children aged 13 to 15 years old have scores on this test above 92? (NOTE: Please enter your answer in decimal form. For example, 45.23% should be entered as 0.4523.) Answer: (b) Enter the score which marks the lowest 30 percent of the distribution Answer: (c) Enter the score which...
scores on a certain intelligence test for children between ages 13 and 15 years are approximately...
scores on a certain intelligence test for children
between ages 13 and 15 years are approximately normally distributed
with u= 106 o=18
om a and a Il be- 20. (1 point) Scores on a certain intelligence test for chil- dren between ages 13 and 15 years are approximately normally distributed with u= 106 and o=18. (a) What proportion of children aged 13 to 15 years old have scores on this test above 96 ? (NOTE: Please enter your answer in...
(1 t) Scores on a tan inteligence test for children between ages 13 and between ages...
(1 t) Scores on a tan inteligence test for children between ages 13 and between ages 13 and 1 5 years are approximately normally distributed with 101 and of children aged 13 to 15 years old have scores on this test above 87 2 NOTE: Please enter your answer in decimal form. For example, 45.23% should be entered as 0.4523.) Answer: 7823 (b) Enter the score which marks the lowest 30 percent of the distribution Answer (G) Enter the score...
Scores on a certain intelligence test for children between ages 13 and 15 years are approximately...
Scores on a certain intelligence test for children between ages 13 and 15 years are approximately normally distributed with ?=101 and ?=15. (a) What proportion of children aged 13 to 15 years old have scores on this test above 91 ? (Reminder: proportions are between 0 and 1 - don't put in percentages!) (b) Enter the score which marks the lowest 25 percent of the distribution. (c) Enter the score which marks the highest 5 percent of the distribution.
Scores on a certain intelligence test for children between ages 13 and 15 years are approximately...
Scores on a certain intelligence test for children between ages 13 and 15 years are approximately normally distributed with ?=106 and ?=21. (a) What proportion of children aged 13 to 15 years old have scores on this test above 88 ? (Reminder: proportions are between 0 and 1 - don't put in percentages!) Answer: (b) Enter the score which marks the lowest 25 percent of the distribution. Answer: (c) Enter the score which marks the highest 5 percent of the...
1.The heights of women aged 20 to 29 follow approximately the N(64, 2.57) distribution. Men the...
1.The heights of women aged 20 to 29 follow approximately the N(64, 2.57) distribution. Men the same age have heights distributed as N(69.3, 2.8). What percent of young men are shorter than the mean height of young women? 2. Changing the mean and standard deviation of a Normal distribution by a moderate amount can greatly change the percent of observation in the tails. Suppose that a college is looking for applicants with SAT math scores 760 and above. (a) In...
(3 points) In its Fuel Economy Guide for 2008 model vehicles, the Environmental Protection Agency...
(3 points) In its Fuel Economy Guide for 2008 model vehicles, the Environmental Protection Agency gives data on 1152 vehicles. There are a number of outliers, mainly vehicles with very poor gas mileage. If we ignore the outliers, however, the combined city and highway gas mileage of the other 1120 or so vehicles is approximately Normal with mean 18.7 miles per gallon (mpg) and standard deviation 4.3 mpg The 2008 Chevrolet Malibu with a four-cylinder engine has combined gas mileage...
Chapter 7: Problem 13 Previous Problem Problem List Next Problem (1 point) The scores of students...
Chapter 7: Problem 13 Previous Problem Problem List Next Problem (1 point) The scores of students on the SAT college entrance examinations at a certain high school had a normal distribution with mean μ 545.3 and standard deviation σ .: 29.9 (a) What is the probability that a single student randomly chosen from all those taking the test scores 551 or higher? ANSWER: For parts (b) through (d), consider a simple random sample (SRS) of 30 students who took the...
Previous Problem Problem List Next Problem (2 points) Among drivers who have had a car crash...
Previous Problem Problem List Next Problem (2 points) Among drivers who have had a car crash in the last year, 220 were randomly selected and categorized by age, with the results listed in the table below. Age Under 25 25-44 45-64 Over 64 Drivers 83 50 34 53 If all ages have the same crash rate, we would expect (because of the age distribution of licensed drivers) the given categories to have 16%, 44%, 27%, 13% of the subjects, respectively....
Homework6: Problem 5 Previous Problem List Next (1 point) Almost all medical schools in the United...
Homework6: Problem 5 Previous Problem List Next (1 point) Almost all medical schools in the United States require applicants to take the Medical College Admission Test (MCAT). On one exam, the scores of all applicants on the biological sciences part of the MCAT were approximately normal with mean 9.4 and standard deviation 2.1. For applicants who actually entered medical school, the mean score was 10.5 and the standard deviation was 1.7. Note: Enter your answers in the form 74.22%, not...
(1 point) Scores on a certain intelligence test for children between ages 13 and 15 years are approximately normally distributed with 27 u= 106 and o (a) What proportion of children aged 13 to 15 years old have scores on this test above 92? (NOTE: Please enter your answer in decimal form. For example, 45.23% should be entered as 0.4523.) Answer: (b) Enter the score which marks the lowest 30 percent of the distribution Answer: (c) Enter the score which...
scores on a certain intelligence test for children
between ages 13 and 15 years are approximately normally distributed
with u= 106 o=18
om a and a Il be- 20. (1 point) Scores on a certain intelligence test for chil- dren between ages 13 and 15 years are approximately normally distributed with u= 106 and o=18. (a) What proportion of children aged 13 to 15 years old have scores on this test above 96 ? (NOTE: Please enter your answer in...
(1 t) Scores on a tan inteligence test for children between ages 13 and between ages 13 and 1 5 years are approximately normally distributed with 101 and of children aged 13 to 15 years old have scores on this test above 87 2 NOTE: Please enter your answer in decimal form. For example, 45.23% should be entered as 0.4523.) Answer: 7823 (b) Enter the score which marks the lowest 30 percent of the distribution Answer (G) Enter the score...
(3 points) In its Fuel Economy Guide for 2008 model vehicles, the Environmental Protection Agency gives data on 1152 vehicles. There are a number of outliers, mainly vehicles with very poor gas mileage. If we ignore the outliers, however, the combined city and highway gas mileage of the other 1120 or so vehicles is approximately Normal with mean 18.7 miles per gallon (mpg) and standard deviation 4.3 mpg The 2008 Chevrolet Malibu with a four-cylinder engine has combined gas mileage...
Chapter 7: Problem 13 Previous Problem Problem List Next Problem (1 point) The scores of students on the SAT college entrance examinations at a certain high school had a normal distribution with mean μ 545.3 and standard deviation σ .: 29.9 (a) What is the probability that a single student randomly chosen from all those taking the test scores 551 or higher? ANSWER: For parts (b) through (d), consider a simple random sample (SRS) of 30 students who took the...
Previous Problem Problem List Next Problem (2 points) Among drivers who have had a car crash in the last year, 220 were randomly selected and categorized by age, with the results listed in the table below. Age Under 25 25-44 45-64 Over 64 Drivers 83 50 34 53 If all ages have the same crash rate, we would expect (because of the age distribution of licensed drivers) the given categories to have 16%, 44%, 27%, 13% of the subjects, respectively....
Homework6: Problem 5 Previous Problem List Next (1 point) Almost all medical schools in the United States require applicants to take the Medical College Admission Test (MCAT). On one exam, the scores of all applicants on the biological sciences part of the MCAT were approximately normal with mean 9.4 and standard deviation 2.1. For applicants who actually entered medical school, the mean score was 10.5 and the standard deviation was 1.7. Note: Enter your answers in the form 74.22%, not...
Most questions answered within 3 hours.
-
In 2005, Derrek Lee led the National Baseball League with a
0.335 batting average, meaning that...
asked 10 minutes ago -
Write a recursive function moreFactors(a,b,fact) that does the
following:
1. Takes as an input 3 positive...
asked 9 minutes ago -
In order for corporations to behave ethically, they must,
ultimately, give up the profit motive.
...
asked 10 minutes ago -
Blue Spruce Corp. owns equipment that cost $63,400 when
purchased on January 1, 2017. It has...
asked 30 minutes ago -
A lottery exists where balls numbered 1 to 17 are placed in an
urn. To win,...
asked 1 hour ago -
Please explain steps:
An 80 kg swimmer steps off a platform 10 m above the water...
asked 1 hour ago -
26) Briefly describe, using words or simple diagrams, the
chemiosmotic theory for coupling oxidation to phosphorylation...
asked 3 hours ago -
Suppose that XX is a random variable with mean 16 and standard
deviation 5 . Also...
asked 4 hours ago -
Calculate the number density of argon gas at a temperature of
24C and a pressure of...
asked 7 hours ago -
Alternative
Classification
How to Estimate
Probabilities from Data? ( For continuous Attributes)
And How to generate...
asked 7 hours ago -
An explosion breaks a 20.0-kg object into three parts. The
object is initially moving at a...
asked 8 hours ago -
Calculate the approximate number of residues of Rubisco, which
is involved in carbon fixation in plants,...
asked 9 hours ago