Posted by **LT** on Wednesday, October 17, 2007 at 2:24pm.

1) Find the missing parameter

1.mean 15, 30.15 %, above 50; what is the standard deviation

2.mean 75, 5.05% below 30; what is the standard deviation

3.standard deviation 9, 85.08% below 105: what is the mean

4.standard deviation 16.8, 15.62% above 18.3: what is the mean

- Statistics -
**PsyDAG**, Thursday, October 18, 2007 at 12:24pm
Z = (raw score - mean)/standard deviation

Look up the percentage in a table in the back of your stat text labeled something like "areas under a normal distribution" to get your Z score value.

Insert the values into the equation above and solve for the unknown.

I hope this helps. Thanks for asking.

- Statistics -
**Anonymous**, Tuesday, July 2, 2013 at 9:45am
what is the probabilty of a sample of 25 houses will be tetween 145 and 160 days

## Answer this Question

## Related Questions

- Statistics - 1) A Motor Company has purchased steel parts from a supplier for ...
- Math - Roughly speaking, the standard deviation indicates how far, on average, ...
- Math: Statistics - My homework has a list of numbers and I'm working with ...
- Foundations of Measurement - Approximately 400,000 students took the GRE in 2009...
- statistics/mean and standard deviation - find the mean and standard deviation in...
- statistic - 1. A distribution has a standard deviation of 12. Find the z-...
- Statistics - data from sample of 400 cases, variable has 95% confidence interval...
- Stastics - When we convert x-value to z- score and use Standard Normal ...
- math - Suppose x is a random variable with mean and standard deviation. If a ...
- statistics - find the probability that the sample mean falls between 1.6 and 2.2...