Question
In: Statistics and Probability
In a large population of college-educated adults, the mean IQ is 118 with a standard deviation...
In a large population of college-educated adults, the mean IQ is 118 with a standard deviation of 20. Suppose 200 adults from this population are randomly selected for a market research campaign. The probability that the sample mean IQ is greater than 120 is Select one: a. 0.0001. b. 0.0790. c. 0.1230. d. 0.9210. e. Cannot be determined
Solutions
Expert Solution
Solution :
Given that ,
mean = 
= 118
standard deviation = 
= 20
n = 200
= 118 and
=
/ 
n = 20 /
200 = 1.4142
P(
> 120) = 1 - P(
< 120)
= 1 - P((
-
) /
< (120 - 118) / 1.4142 )
= 1 - P(z < 1.412)
= 1 - 0.9210
= 0.0790
Probability = 0.0790
option b) is correct
orchestra answered 1 year agoRelated Solutions
In a large population of college-educated adults, the mean IQ is 112 with standard deviation 25....
In a large population
of college-educated adults, the mean IQ is 112 with standard
deviation 25. Suppose 100 adults from this population are randomly
selected for a market research campaign.
What is the
probability that the sample mean IQ is lower than 105?
The mean population IQ is 100 with a standard deviation of 15. A principal at a...
The mean population IQ is 100 with a standard deviation of 15. A
principal at a certain school claims that the mean IQ score of
their students in his school is greater that 100. A random sample
of 30 students IQ scores have a mean score of 112. Significance
level α = 0.01
(a) State the null and alternate hypotheses
(b) Calculate the z statistic value 6
(c) Determine the p value. Sketch the graph
(d) Make a decision. Reject...
IQ scores in a large population have a normal distribution with mean=100 and standard deviation=15. What...
IQ scores in a large population have a normal
distribution with mean=100 and standard deviation=15. What is the
probability the sample mean for n=2 will be 121 or higher?
(I understand the z score equals 1.98,could you please
explain to me how the final answer is equal to
0.0239?thanks.)
Also, why do we use 1 and subtract 0.9761 to get 0.0239? Where does
0.9761 come from?
Assume the population mean IQ is 100 with a standard deviation of 15. A sample of...
Assume the population mean IQ is 100 with a standard deviation
of 15. A sample of 25 students recently took an IQ test in which
their average score was 108. If another sample of 25 students was
selected, what is the probability that that sample would have a
mean greater than 108?
A certain IQ test is known to have a population mean of 100 and standard deviation...
A certain IQ test is known to have a population mean of 100 and
standard deviation of 15 in the general population. You want to
test whether psychology majors have a different average IQ than the
population as a whole. Assume the variance of IQ is the same for
Psych majors as it is in the general population.
Suppose that Psychology majors actually have an average IQ of
108. If you do a 2-tailed test at α= .05 with a...
A standardized college admissions test has a population mean of 65, a population standard deviation of...
A standardized college admissions test has a population
mean of 65, a population standard deviation of 10 points, and is
normally distributed. If a student scores a 73 on the test, above
what percentage of the test-takers does her score fall? Be sure to
show your calculations.
Assume that adults have iq scores that are normally distributed with a mean of µ =100 and standard deviation of 20
Assume that adults have iq scores that are normally distributed with a mean of µ =100 and standard deviation of 20.find the probability that a randomly selected adult has an iq less than 128?
In the population, the average IQ is 100 with a standard deviation of 15. A team...
In the population, the average IQ is 100 with a standard
deviation of 15. A team of scientists wants to test
a new medication to see if it has either a positive or negative
effect on intelligence, or no effect at all. A
sample of 30 participants who have taken the medication has a
mean of 105. It is assumed that the data are
drawn from a normally distributed population. Did the medication
affect intelligence, using
α= 0.05?
a. State...
In the population, the average IQ is 100 with a standard deviation of 15. A team...
In the population, the average IQ is 100 with a standard
deviation of 15. A team of scientists wants to test a new
medication to see if it has either a positive or negative effect on
intelligence, or no effect at all. A sample of 30 participants who
have taken the medication has a mean of 105. It is assumed that the
data are drawn from a normally distributed population. Did the
medication affect intelligence, using α = 0.05?
(a)...
Suppose that the IQ of adults is normally distributed with a mean of 100 and standard...
Suppose that the IQ of adults is normally distributed with a
mean of 100 and standard deviation of 15.
(a) What IQ score distinguishes the highest 10%?
(b) What is the probability that a randomly selected person has
an IQ score between 91 and 118?
(c) Suppose people with IQ scores above 125 are eligible to join
a high-IQ club. Show that approximately 4.78% of people have an IQ
score high enough to be admitted to this particular club.
(d)...
ADVERTISEMENT
ADVERTISEMENT
Latest Questions
- Using the Stack class (it's on the class web page) construct a program that will evaluate...
- An old two-flat can be purchased for $200,000 cash. The two units can bring in a...
- Please code in C# - (C - Sharp) Assignment Description Write out a program that will...
- Geraldine Wolfe is a supervisor at Fantastigifts. She has an annual salary of $45,500, paid biweekly,...
- Employees present a serious threat to the security of an organization. Give four reasons why employees...
- Do not neglect the old for the new. The existing business must not lose priority simply...
- (10 pts) Explain why modern computers consist of multiple abstract levels and describe the main functions...
ADVERTISEMENT