Exam scores of a very easy test follow a negatively skewed distribution. These scores have µ...
Exam scores of a very easy test follow a negatively skewed distribution. These scores have µ = 50 and σ = 15. Eric got 61 on this exam. Which of the following statements must be correct?
Question 50.5 pts
Exam scores of a very easy test follow a negatively skewed distribution. These scores have µ = 50 and σ = 15. Eric got 61 on this exam. Which of the following statements must be correct?
| (A) 50% of the class got scores above 50. |
| (B) Eric did better than 76.73% of his classmates. |
| (C) Eric did better than 73% of his classmates |
| (D) there is not enough information to calculate probabilities as we don’t have a normal distribution |
Homework Answers
We can work with the probabilities if the curve looks like
this:
i.e A normal distribution which is a symmetric curve.
However, in this case the distribution is negatively skewed( left
skewed ) like this:
Here the curve is not symmetric hence we can't calculate the
percentile of Eric's score.
Ans. (D) there is not enough information to calculate
probabilities as we don't have a normal distribution.
Add Answer to:
Exam scores of a very easy test follow a negatively
skewed distribution. These scores have µ...
A distribution with µ = 55 and σ = 6 is being standardized so that the...
A distribution with µ = 55 and σ = 6 is being standardized so that the new mean and standard deviation will be µ = 50 and σ = 10. When the distribution is standardized, what value will be obtained for a score of X = 58 from the original distribution? a.58 b.55 c.61 d.53 On an exam with μ = 52, you have a score of X = 56. Which value for the standard deviation would give you the...
When Lorenzo finished his exam last week, he thought the test was over. But Dr. Hale...
When Lorenzo finished his exam last week, he thought the test was over. But Dr. Hale put z-scores on each student's paper and asked them to figure out their original score. The mean for the class is µ = 61 and standard deviation is σ = 8. Lorenzo's z-score is +1.75. What did he score on the exam?
Suppose test scores on a certain exam follow a normal distribution with μ = 70. If...
Suppose test scores on a certain exam follow a normal distribution with μ = 70. If 8% of students scored above 80, what is the standard deviation of the distribution?
11. A distribution of exam scores has a mean of μ = 78. a.If your score...
11. A distribution of exam scores has a mean of μ = 78. a.If your score is X = 70, which standard deviation would give you a better grade: σ = 4 or σ = 8? Answer: ________________ b.If your score is X = 80, which standard deviation would give you a better grade: σ = 4 or σ = 8? Answer: ___________________ 12. For each of the following, identify the exam score that should lead to the better grade....
#3 One of the most common ways of measuring intelligence is the IQ test. IQ scores...
#3 One of the most common ways of measuring intelligence is the IQ test. IQ scores in the US population have an average of µ = 100 and a standard deviation of σ = 15. Suppose a researcher wanted to test whether socioeconomic status (SES) has an effect on IQ scores. The researcher takes a random sample of n = 100 people, selected from a list of the 1000 richest people in the United States. a. Based on this information,...
The test scores on a 100-point test were recorded for 20 students. 61 94 91 85...
The test scores on a 100-point test were recorded for 20 students. 61 94 91 85 54 74 85 83 77 93 89 99 91 71 86 67 | 94 | 76 96 83 | (a) Use a stem and leaf plot to describe the data. (Enter numbers from smallest to largest separated by spaces. Enter NONE for stems with no values.) 1,7 1,4,6,7 3,3,5,5,6,9 9 1,1,3,4,4,6,9 (b) Describe the shape and location of the scores. The distribution is mound...
The scores on the SAT verbal test in recent years follow approximately the N(539, 111) distribution....
The scores on the SAT verbal test in recent years follow approximately the N(539, 111) distribution. Use technology to answer these questions. a) If a student placed in the bottom 10% of all students taking the SAT, what was his score below? State answer as a whole number. _______________ b)How high must a student score to place in the top 10% of all students taking the SAT? State answer as a whole number. ___________________
Question 2 3 pts The boxplots below show the distribution of test scores for two classes....
Question 2 3 pts The boxplots below show the distribution of test scores for two classes. Class A Class B 0 10 20 30 40 50 60 70 80 90 100 Test scores Which of the following statements is a valid conclusion that can be drawn from the boxplots? Choose all that apply. Class A and B have approximately the same percentage of students who scored 70 or higher on the test. Class A has a greater percentage of students...
A psychologist believes that students' test scores will be affected if they have too much caffeine...
A psychologist believes that students' test scores will be affected if they have too much caffeine before taking an exam. To examine this, she has a sample of n= 15 students drink five cups of coffee before taking an exam. She uses an exam that has a population mean of μ=72 and a population standard deviation of σ = 3. The mean test score for the sample of 15 students who drank five cups of coffee before taking the exam...
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...
The test scores on a 100-point test were recorded for 20 students. 61 94 91 85 54 74 85 83 77 93 89 99 91 71 86 67 | 94 | 76 96 83 | (a) Use a stem and leaf plot to describe the data. (Enter numbers from smallest to largest separated by spaces. Enter NONE for stems with no values.) 1,7 1,4,6,7 3,3,5,5,6,9 9 1,1,3,4,4,6,9 (b) Describe the shape and location of the scores. The distribution is mound...
Question 2 3 pts The boxplots below show the distribution of test scores for two classes. Class A Class B 0 10 20 30 40 50 60 70 80 90 100 Test scores Which of the following statements is a valid conclusion that can be drawn from the boxplots? Choose all that apply. Class A and B have approximately the same percentage of students who scored 70 or higher on the test. Class A has a greater percentage of students...
Most questions answered within 3 hours.
-
Where is the error in this code sequence?
String s1 = "Hello";
String s2 = "ello";...
asked 11 months ago -
Financial data for Joel de Paris, Inc., for last year
follow:
Joel de Paris, Inc.
Balance...
asked 11 months ago -
Consider this reaction:
Al2(SO4)3 (aq)+ BaCl3
(aq) Al2Cl6 (aq)- +
3BaSO4(s) . What is the...
asked 11 months ago -
Suppose that Savneet is considering increasing her
recent random sample from 20 car rentals to 40...
asked 11 months ago -
Trucks arrive at an unloading terminal at an average rate of 120
per hour.
Trucks arrive...
asked 11 months ago -
Why are methanol and ethanol completely soluble in water while
octanol is not very little soluble....
asked 11 months ago -
A facilities manager at a university reads in a research report
that the mean amount of...
asked 11 months ago -
When the CuSO4 is rehydrated by adding water to the anhydrous
compound, is this an endothermic...
asked 11 months ago -
A ray of sunlight is passing from diamond into crown glass; the
angle of incidence is...
asked 11 months ago -
A block of mass 0.249 kg is placed on top of a light, vertical
spring of...
asked 11 months ago -
how do the kidneys compensate in the presences of acidosis
a) trigger hyperventilate
b) reserve acid...
asked 11 months ago -
Question 501 pts
The rental rate of capital to the firm increases. Which of the
following...
asked 11 months ago