Saturday

March 28, 2015

March 28, 2015

Posted by **Ashley** on Monday, November 26, 2012 at 8:46pm.

a.what is the probability that a student sends more than 250 messsages a day?

b.what is the probability that student sends less than 150 text messages a day?

c.what is the probability that a student sends between 180 and 240?

d.what is the probability that a student ssends exactly 250 text messages a day?

e.find the cutoff number fot the middle 60% of text messages sent per day?

f. find the top 25% of the number of text messages sent per day?

g.find the bottom 10% of text messages sent per day

- statistics -
**PsyDAG**, Tuesday, November 27, 2012 at 2:36amZ = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions for the Z scores.

For e, f, g, find the proportion first and use the Z score in the above equation.

Here is the graph:

http://en.wikipedia.org/wiki/Standard_deviation

**Answer this Question**

**Related Questions**

statistics - Use the following information to calculate the lower and upper ...

Math - A college student is using the following model to determine the total ...

statistics - A statistics professor receives an average of five e-mail messages ...

statistics - A teacher was interested in how many text messages teenagers got ...

statistics - The time a student spends in the shower on any school day is an ...

statistics - A widget factory's worker productivity is normally distributed. one...

Statistics - It takes the bus an average of 20 minutes to arrive at a certain ...

statistics and probability - It is known that an exam scores of students in STAT...

Science - A student observed the apparent shape of the moon every night for a ...

Check answers please Statistics - Suppose that each student in stat. has a 9% ...