You are a graduate student in psychology administering IQ tests to clients, usin

Question

You are a graduate student in psychology administering IQ tests to clients, using the Wechsler Adult Intelligence Scale (WAIS) as your chosen IQ test. You know that the population mean and standard deviation for the raw intelligence test scores are = 80 and = 13. As indicated in the manual, the developers of the test use a standardized distribution with a mean and standard deviation for the WAIS scores of = 100 and = 15. Each raw score is transformed into a standardized score to ease interpretation. For each client below, calculate the missing scores. Round to no less than four decimal places until final answer, and no less than two decimal places for final answer.

After testing all your clients, you find that their mean raw score is 82 (n = 150). What is the probability of selecting a random sample of n = 150 scores with a sample mean this large or larger? ______________

Another graduate student told you she obtained a standardized score sample mean of 98 for her clients (n = 120). What is the probability of selecting a random sample of n = 120 scores with a sample mean this large or larger? ______________

Explanation / Answer

1)here std error of mean =std deviation/(n)1/2 =13/(150)1/2 =1.0614

probability of selecting a random sample of n = 150 scores with a sample mean this large or larger=P(X>82)

=1-P(X<82)=1-P(Z<(82-80)/1.0614)=1-P(Z<1.8842)=1-0.9702=0.0298

2) std error of mean =std deviation/(n)1/2 =15/(120)1/2 =1.3693

probability of selecting a random sample of n = 120 scores with a sample mean this large or larger=P(X>98)

=1-P(X<98)=1-P(Z<(98-100)/1.3693)=1-P(Z<-1.4606)=1-0.0721 =0.9279

revert for any clarification required

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.