# math

the u.s weather bureau has provided the following information about the total annual rainfall (in inches) in hawaii for the years 1965 to 1984.
15 12 31.5 17 11.2 13 12.4 16.3 14.6 10 12.8 14.1 14.7 10.7 15.2 10.9 18.4 12 15.9 10
a) use Chebyshev's theorem to find an interval centered about the mean for the annual rain fall in which you would expect at least 88.9% of the years to fall.

b)use Chebyshev's theorem to find an interval centered about the mean for the annual rain fall in which you would expect at least 75% of the years to fall.

c)for the data given above find the median and the coefficent of variation.

I will try to keep this simple add all the rainfall numbers up (287.7) divide by how many parts you had (20)=14.385 this is your mean.

Make a chart with three columns the first will be each individual rainfall amount. Second column will be each amount with the mean subtracted from it. Third column will be the number in column 2 squared.

ex:
15 .615 .378
12 -2.385 5.688
31.5 17.115 292
17 2.615 6.838

do this for all 20.
add up column 3 you should get 417.1855

now you divide that total (417.1855) by n-1 (20-1=19) 417.1855/19=21.957 this is your variance. take the square root of the variance and you get standard deviation (4.686).
Finally part of the answer take standard deviation/mean to get coeffecient of variation (4.686/14.385= .325756) so 32.57%

Cheby just puts bounds on how much data must lie close to the mean. Here comes the whole 1-(1/k^2). k has to be 3.3333 to equal 88.9% and k has to be 2 to equal 75%.
Now we take the mean (14.385)and subtract k (3.3333)*standard dev(4.686)
14.385-15.61998=-1.235 to get the bottom of the interval. to get the top add 3.3333*standard dev to the mean 14.385+15.61998=30.005.
the 75 % question is just making k=2
14.385- (2)(4.686)=5.013
14.385+ (2)(4.686)=23.757.

to get the medain sort all your dat in order 10, 10, 10.7, 10.9, 11.2, 12, 12, 12.4,12.8, 13, 14, 14.6, 14.7,15, 15.2, 15.9, 16.3, 17, 18.4, 31.5. cross off the two end numbers until you get to the middle 10 gone 31.5 gone 10 gone 18.4 gone etc... if you have an odd number that middle one is the median in this case you have an even amount so you take the average of 13 and 14 to get13.5. Hope this helped

1. 👍 0
2. 👎 0
3. 👁 114

## Similar Questions

1. ### computer services

I need help to find more information about the computer service bureau Can anyone help me? What do I need to look under? The question I have to answer is "When the computer service bureau destroys or erases records, should the

asked by Sharon on July 8, 2008
2. ### Statistics

Please help!!! 3. A one-legged, red-nosed tramp approaches John in the park and tells him he can predict the next day’s weather perfectly after he has drunk a shot of “Ripple” wine (cost of one shot: \$0.50). If the tramp is

asked by Linda on August 25, 2011
3. ### Science

How do meteorologists combine data from weather radar and weather satellites to gather information about the atmosphere?

asked by SoccerStar on October 16, 2012
4. ### Science

When trying to predict, tomorrow's weather, what area would you most want weather information about?

asked by Traci on January 7, 2009
5. ### Statistics

4. John sells ice cream bars at the local park. He buys the bars for \$1.20 per dozen and sells them for \$0.15 each. If it is a rainy day at the park, he can sell nothing; if is overcast, he sells one dezen bars; and if is sunny,

asked by Linda on August 25, 2011
6. ### Statistics

4. John sells ice cream bars at the local park. He buys the bars for \$1.20 per dozen and sells them for \$0.15 each. If it is a rainy day at the park, he can sell nothing; if is overcast, he sells one dezen bars; and if is sunny,

asked by Linda on August 25, 2011
7. ### science

Name 3 ways to find out about the weather in our area.choose which one is the best for finding the information right away.choose which one is the best for predicting weather in future

asked by jil on October 18, 2008
8. ### Criminal Justice

Disclosure of PSI information enables the defendant to contest information that he or she considers unfair and to be protected from the effects of unfounded information, but disclosure may cause all of the following EXCEPT: A.

asked by Amy on June 25, 2015
9. ### Critical thinking

Do not guess or jump to conclusions. (In this step, describe how you found if you have the necessary information to proceed. For example, explain how you identified what information is provided and what information must be

asked by Tara on July 4, 2010
10. ### Critical thinking

Do not guess or jump to conclusions. (In this step, describe how you found if you have the necessary information to proceed. For example, explain how you identified what information is provided and what information must be

asked by Tara on July 4, 2010
11. ### physics help!!!

A hypothetical spherical planet consists entirely of iron (p=7860kg/m^3). Calculate the period of a satellite that orbits just above its surface. I really can't solve this! No other information was provided. Please and thank you

asked by Anonymous on March 3, 2010

More Similar Questions