The Stanford-Binet IQ test has scores that are normally
distributed with a mean of 100. A...
The Stanford-Binet IQ test has scores that are normally
distributed with a mean of 100. A principal in an elementary school
believes that her students have above average intelligence and
wants verification of her belief. She randomly selects 20 students
and checks the student files. She finds the following IQ scores for
these 20 students. IQ scores: 110,132, 98, 97, 115, 145, 77, 130,
114, 128, 89, 101, 92, 85, 112, 79, 139, 102, 103, 89
a. Compute the sample...
A Psychology professor, teaching at a large university, wants to
know whether there is a difference...
A Psychology professor, teaching at a large university, wants to
know whether there is a difference between the IQs of male and
female students in attendance. She randomly and independently
selects 20 female and 20 male students and has them take the IQ
test. The resulting IQ data are as follows:
Female: 130, 117, 124, 120, 125, 109, 100, 118, 127, 130, 126, 118,
131, 104, 130, 116, 122, 115, 129, 117
Male: 106, 114, 134, 120, 107, 131, 133,...
You know that the US population in 1980 had an average IQ score
of 100, with...
You know that the US population in 1980 had an average IQ score
of 100, with a standard deviation of 1.5. The data records
information on 900 young males (26 to 36 years old) from NLSY (the
National Longitudinal Surveys), surveys conducted in 1980, show an
average IQ score of 101. As a result, you suspect that the young
males have a slightly higher average IQ than the population. If the
standard deviation of the IQ scores for them is...