In a large population of adults, the mean IQ and standard deviation are
respectively.
Suppose 200 adults are randomly selected for a market research campaign. What is the probability that the sample mean is less than 110?
Solution :
Given that ,
mean = = 112
standard deviation = = 20
n = 200
= 112
= / n = 20/ 200=1.4142
P( <110 ) = P[( - ) / < (110 -112) / 1.4142]
= P(z < -1.41)
Using z table
= 0.0793
probability=0.0793
In a large population of adults, the mean IQ and standard deviation are respectively. Suppose 200...
In a large population of adults, the mean IQ is 112 with a standard deviation of 20. Suppose 200 adults are randomly selected for a market research campaign. The probability that the sample mean IQ is greater than 110 is...?
In a large population of adults, the mean IQ is 112 with a standard deviation of 20. Suppose 200 adults are randomly selected for a market research campaign. The sampling distribution of the sample mean IQ is a. approximately Normal, mean 112, standard deviation 20. ob approximately Normal, mean 112, standard deviation 1.414. approximately Normal, mean 112, standard deviation 0.1. d. exactly Normal, mean 112, standard deviation 20.
In a large population of prisoners, the mean IQ is 95 with a standard deviation of 15. 250 adults from this population are randomly selected for a survey of attitudes toward crime. a. What is the mean of this sampling distribution (all samples of n = 250)? b. What is the standard deviation of the sampling distribution? c. What is the shape of sampling distribution? d. If an individual prisoner has an IQ of 90, is she a likely or...
The standard IQ test is designed so that the mean is 100 and the standard deviation is 15 for the population of all adults. We wish to find the sample size necessary to estimate the mean IQ score of statistics students. Suppose we want to be 96% confident that our sample mean is within 1 IQ points of the true mean. The mean for this population is clearly greater than 100 . The standard deviation for this population is probably...
Assume that adults have IQ scores that are normally distributed with a mean of μ = 105 and a standard deviation = 15 Find the probability that a randomly selected adult has an IQ less than 129.The probability that a randomly selected adult has an IQ less than 129 is _______ (Type an integer or decimal rounded to four decimal places as needed)
assume that adults have IQ scores that are normally distributed with a mean of 100 and a standard deviation of 20. find the probability that a randomly selected adult has an IQ less than 20.
The IQ scores of adults are normally distributed with a mean 100 and a standard deviation of 15. If a group of 64 adults is randomly selected, what is the probability that their mean IQ will be at least 95? A. 0.6293 B. 0.3707 C. 0.9962 D. 0.0038
For randomly selected adults, IQ scores are normally distributed with a standard deviation of 15. For a simple random sample of 25 randomly selected college students, their IQ scores have a standard deviation of 18. Use a 5% level of significance; test the claim that the IQ scores of college students are less consistent (higher standard deviation) compare to the IQ scores of the general population.
Assume that adults have IQ scores that are normally distributed with a mean of μ 105 and a standard deviation 20. Find the probability that a randomly selected adult has an IQ less than 137. The probability that a randomly selected adult has an IQ less than 137 is: (Type an integer or decimal rounded to four decimal places as needed.)
A population has a mean of 200 and a standard deviation of 60. Suppose a sample of size 100 is selected and is used to estimate . What is the probability that the sample mean will be within +/- 5 of the population mean (to 4 decimals)? What is the probability that the sample mean will be within +/- 16 of the population mean (to 4 decimals)?