1. ## stressed dad needs help!

Hi, I am new to the forum and need help with a question from my daughter studying first year business, can anybody supply the answer below....thanks

. The weekly salary paid to employees of a small company that supplies part-time laborers averages $700 with a standard deviation of$400.

1) If the weekly salaries are normally distributed, estimate the fraction of employees that make more than $300 per week. 2) If every employee receives a year-end bonus that adds$100 to the paycheck in the final week, how does this change the normal model for that week?

3) If every employee receives a 5% salary increase for the next year, how does the normal model change?

4) If the lowest salary is $300 and the median salary is$500, does a normal model appear appropriate?

2. ## Re: stressed dad needs help!

Question 1 requires the use of the 68, 95, 99.7 rule. Does your daughter know that?

3. ## Re: stressed dad needs help!

Originally Posted by ericthered
Hi, I am new to the forum and need help with a question from my daughter studying first year business, can anybody supply the answer below....thanks

. The weekly salary paid to employees of a small company that supplies part-time laborers averages $700 with a standard deviation of$400.

1) If the weekly salaries are normally distributed, estimate the fraction of employees that make more than $300 per week. Do you or your daughter know what the "normal distribution" is? The "standard normal distribution" variable would be z= (x- 700)/400. Here, x= 300 so this is (300- 700)/400= -400/400= -1. So what is P(-1) in the standard normal distribution? There is no simple way to "calculate" that- you have to look it up in a table of the normal distribution. There is a good one at Standard Normal Distribution Table. 2) If every employee receives a year-end bonus that adds$100 to the paycheck in the final week, how does this change the normal model for that week?
Adding $100 one week clearly changes the mean- by how much? Do you think it would change the standard deviation? 3) If every employee receives a 5% salary increase for the next year, how does the normal model change? Increasing the salary by 5% increases the mean by 5%. 4) If the lowest salary is$300 and the median salary is \$500, does a normal model appear appropriate?
That clearly depends upon what YOU consider "appropriate"!

4. ## Re: stressed dad needs help!

Thanks for help will look further into this!

5. ## Re: stressed dad needs help!

Thanks for help will look further into this1

6. ## Re: stressed dad needs help!

Originally Posted by HallsofIvy
Increasing the salary by 5% increases the mean by 5%.
True - and it also increases the standard deviation by 5%.

7. ## Re: stressed dad needs help!

Originally Posted by ebaines
True - and it also increases the standard deviation by 5%.
Yes, thanks.

8. ## Re: stressed dad needs help!

Originally Posted by HallsofIvy
That clearly depends upon what YOU consider "appropriate"!
Not entirely sure I get this response. If the data come from a Normal process than to observe half of all data points lying in an interval that is half a standard deviations width, would suggest that the distribution is HIGHLY right skewed and definitely non-Normal.