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.

Name of Client                  Raw Score             z-score             Standard score

DeMario                                70                    _________ ___________

Lillian.                              __________ _________                     115

*** Show ALL your work and record your answers on this sheet. Round z scores to two decimal places. Do not round the proportions derived from the Unit Normal Table.

What % of the distribution is expected to fall below a raw score of 85? ______________

What % of the distribution is expected to fall below a standardized score of 90? ______________

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

Here we have to find first z=x score-mean/Standard deviation=70-80/13=-10/13=-0.77

For Z=-10/13 , standard score would be,

-10/13=y-meanof y/SDof y

y=mean of y -10/13*SD of y

y=100-10/13*(15)

=1150/13=88.46

LILLIAN:

Standard score y=115

So Z score= 115-100/15=1

for z=1 row score is 1=x-80/13

so X score=80+13=93

P(X<85)=P(Z<85-80/3)=P(Z<1.38)=0.6480

P(y<90)=P(Z<90-100/15)=P(Z<-0.67)=0.2514

Please reamining questions post saperately. Hope above all helpful to You. Thanksa nd God Bless You.

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