Posted by **Belinda** on Tuesday, February 5, 2008 at 10:00pm.

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...?

- math -
**Reiny**, Tuesday, February 5, 2008 at 10:21pm
your z score is (110-112)/20 = -.1

if you have a normal distribution table, look up the probability for that score, you should get .4602

that means the the prob. of a score of less than 110 is .4602

so the prob of getting higher than 110 is 1-.4602

= .5398

here is a nice applet that lets you enter your original values, it graphs it and gives you the results

http://davidmlane.com/hyperstat/z_table.html

## Answer This Question

## Related Questions

- statistics - Use the given information to find the minimum sample size required ...
- statistics - 2. Assume that the population proportion of adults having a college...
- Statistics - The body temperatures of adults are normally distributed with a ...
- Statistics - The average age of chemical engineers is 37 years with a standard ...
- statistics - The scores of students on the ACT college entrance examination in ...
- Statistics - Daily water intake (including water used in drinks such as coffee...
- statistics - Assume that body temperatures of healthy adults are normally ...
- statistics - A specific study found that the average number of doctor visits per...
- Sampling Distribution - Sampling Distribution Complete solutions and ...
- statistic - Suppose a random sample of 25 students is selected from a community ...

More Related Questions