Posted by **Alia** on Friday, January 4, 2013 at 9:28pm.

If X is a normal random variable with mean 11, and if the probability that X is less than 12.10 is .72 , then what is the standard deviation of X?

Select one:

a. 3.00

b. 6.25

c. 2.50

d. 1.25

Please note that the answer for the above is stated as c.2.50. However, my answer comes to 1.89 which is not given as an option and I can't figure out where I'm going wrong so please can anyone help me with this problem.

Thanks.

## Answer this Question

## Related Questions

- Statistics & Probability - If X is a normal random variable with mean 11, and if...
- Statistics - Suppose that the probability distribution of a random variable x ...
- probability - A random experiment of tossing a die twice is performed. Random ...
- STATISTICS - Consider a binomial random variable where the number of trials is ...
- Statisitics:Standard Deviation of Population and o - Standard Deviation of ...
- Statistics and Probability - A computer supply house receives a large shipment ...
- Statistics - Suppose that the probability distribution of a random variable x ...
- Statistics - 1) A Motor Company has purchased steel parts from a supplier for ...
- math - A person’s blood glucose level and diabetesare closely related. Let x be ...
- statistics - Let x be a continuous random variable that is normally distributed ...

More Related Questions