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 that a random chosen individual has a WAIS score of 105 or higher?

(b) What are the mean and standard deviation of the average WAIS score of x for a SRS of 60 people?

(C) What is the Probability that the average WAIS score of an SRS of 60 people is 105 or higher?

Use z-scores and the normal distribution table for these problems.

For example:
a) Use z-score formula: z = (x - mean)/sd

z = (105 - 100)/15 = 0.33

Look at a normal distribution table using z = 0.33 and determine the area under the curve that would represent this z-score and higher (upper tail of the distribution curve). That would then be your probability.

If a sample size is given, that needs to be computed into the formula:
z = (x - mean)/(sd/sqrt of sample size)
Note: sqrt = square root.

I hope this will get you started.

  1. 👍 0
  2. 👎 0
  3. 👁 137
asked by Jason
  1. 理解理解

    1. 👍 0
    2. 👎 0
    posted by 籃調

Respond to this Question

First Name

Your Response

Similar Questions

  1. statistics

    Politicians are interested in knowing the opinions of their constituents on important issues. One administrative assistant to a senator claims that more than 63% of adult women favor stricter gun laws. A recent telephone survey of

    asked by Katelyn on June 27, 2013
  2. Statistics

    Politicians are interested in knowing the opinions of their constituents on important issues. One administrative assistant to a senator claims that more than 63% of adult women favor stricter gun laws. A recent telephone survey of

    asked by Penny on November 4, 2013
  3. psychology

    Time Remaining: 1. If the concept is truck, the prototype might be: (Points: 5) a Ford pick up. bulldozer. gravel eighteen wheeler. personnel carrier. 2. If the prototype is block or ball, the concept is: (Points: 5) construction.

    asked by tj on November 2, 2011
  4. statistics

    The Intelligence Quotient (IQ) test scores for adults are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability we could select a sample of 50 adults and find the mean of this sample is

    asked by Trev on November 11, 2012
  5. statistics

    It is known that the population mean for the Full Scale IQ of the WAIS is 100 with a standard deviation of 15. A researcher assesses a sample of 200 adults and find that they have a mean Full Scale IQ of 102. The point estimate of

    asked by Katie on April 15, 2014
  6. statistics

    It is known that the population mean for the Full Scale IQ of the WAIS is 100 with a standard deviation of 15. A researcher assesses a sample of 200 adults and find that they have a mean Full Scale IQ of 102. The point estimate of

    asked by Stacey on April 16, 2014
  7. statistics

    It is known that the population mean for the Full Scale IQ of the WAIS is 100 with a standard deviation of 15. A researcher assesses a sample of 200 adults and find that they have a mean Full Scale IQ of 102. The point estimate of

    asked by Sally on April 14, 2014
  8. statistics

    It is known that the population mean for the Full Scale IQ of the WAIS is 100 with a standard deviation of 15. A researcher assesses a sample of 200 adults and find that they have a mean Full Scale IQ of 102. The point estimate of

    asked by Katie on April 15, 2014
  9. PSY

    Please help I get confused on the intelligence descriptions. Appropriately matching the profession with the their greatest area of intelligence. Intelligence Profession Kinesthetic Intelligence Ballet dancer Spatial Intelligence

    asked by Reedy on February 25, 2011
  10. Statistics

    A test of 60 youths and 140 adults showed that 22 of the youths and 10 of the adults were careless drivers. Use a 1% level of significance to test the claim that the youth percentage of careless drivers is higher than the adult

    asked by Polly on July 7, 2010

More Similar Questions