Statistics
posted by Lyndyc .
A normal distribution has a mean of ƒÝ = 100 with ƒã = 20. If one score is randomly selected from this distribution, what is the probability that the score will have a value between X = 90 and X = 110?
a. 0.6915
b. 0.3085
c. 0.1915
d. 0.3830

Statistics 
Kuai
z = (90100)/20 = .5
z table = 0.3085
z = (110100)/20 = .5
z table = 0.6915
0.69150.3085 = 0.3830
D
Respond to this Question
Similar Questions

Statistics
The Wechsler Adult Intelligence Scale (WAIS) is a common "IQ test" for adults. The distribution of WAIS scores for persons over 16 yrs of age is approximately Normal with mean (100) and Standard Deviation 15, (a) Whatis the probability … 
Math
A normal distribution has a mean of 20 and a standard deviation of 3.What is the probability that a randomly selected xvalue from the distribution is: A)at least 14? 
statistics and probability
It is known that an exam scores of students in STAT 2507 follow a normal distribution with a mean of 70% and a standard deviation of 9%. (A) If a student must obtain a mark of 50% to pass the exam, what proportion of students fail … 
statistics
A normal distribution has a mean of µ = 100 with standard deviation = 20. If one score is randomly selected from this distribution, what is the probability that the score will have a value between X = 80 and X = 100? 
statistics
A normal distribution has a mean of 100 and standard deviation of 20. What is the probability of randomly selecting a score less than 130 from this distribution? 
statistics
True or False If one score is randomly selected from a normal distribution with = 100 and = 20, the probability of obtaining a score between X = 80 and X = 120 is 0.3413. 
distribution
In a school, the IQ scores of the students have a normal distribution with a mean value of 100, and a standard deviation of 10. What is the probability that the IQ score of a randomly selected student is at least 120? 
stats
(a) The test had six multiplechoice items that were scored as correct or incorrect, so the total score was an integer between 0 and 6. Do you think that these data are Normally distributed? 
stats
(a) The test had six multiplechoice items that were scored as correct or incorrect, so the total score was an integer between 0 and 6. Do you think that these data are Normally distributed? 
statistics
a normal distribution has a mean of 20 and a standard deviation of 10. Two scores are sampled randomly from the distribution and the second score is subtracted from the first. What is the probability that the difference score will …