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A normal distribution problem |
2009-03-13 |
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jude pose la question :
Regarding the time it takes for an oil change has a normal distribution with a mean of 17.8 minutes and std. deviation of 5.2 minutes. A free oil change will be given to any customer that must wait beyond the guaranteed time. If they don't want to give more than 1% of its customers free oil changes how long should the guarantee be (to the nearest minute). Thank you.
Robert Dawson lui répond. |
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Probability |
2009-03-12 |
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jude pose la question :
) Assuming that the heights of boys in high school basketball are normally distributed with a mean of 70 inches and a std dev. of 2.5 inches, how many boys in a group of 100 are expected to be 75 inches tall.
2) Past records from a bank show that the probability of being approved in the written application for hire is 0.63. Then the probability of being approved by the interview committee is 0.85, given that the candidate has been approved on the written application. What is the probability that a person will be approved on both the written application and the interview?
Robert Dawson lui répond. |
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Stacking eggs |
2009-03-12 |
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Prashanth pose la question :
if you stack two eggs eah in row you must get 1 balance
if you stack three eggs eah in row you must get 2 balance
if you stack four eggs eah in row you must get 3 balance
if you stack five eggs eah in row you must get 4 balance
it goes on like 6 , 7 , 8 and finally
if you stack nine eggs eah in row you must get 8 balance
what would be the answer and how to reach it
Robert Dawson lui répond. |
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A regular decagon is inscribed in a circle |
2009-03-12 |
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Renata pose la question :
A regular decagon is inscribed in a circle of diameter 36 feet. Approximate the perimeter and area of the decagon.
Robert Dawson lui répond. |
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Three consecutive odd integers |
2009-03-11 |
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Susan pose la question :
Find three consecutive odd integers such that the sum of the first, twice the second, and three times the third is 70
Penny Nom lui répond. |
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Water drains from a conical tank |
2009-03-11 |
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Tyler pose la question :
Water drains from a conical tank at the rate of 5ft/min^3. If the initial radius of the tank is 4' and the initial height is 10'.
a) What is the relation between the variables h and r? (height and radius)
b) How fast is the water level dropping when h=6'?
Thanks for the help, i'm stumped.
Penny Nom lui répond. |
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The equation of a line |
2009-03-11 |
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Teresa pose la question :
Write an equation in slope-intercept form that has a horizontal intercept of -7/3 and a vertical intercept of -7/9
Harley Weston lui répond. |
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A sequence |
2009-03-11 |
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Vly pose la question :
2; 6; 26;126;626 find the nth term
Harley Weston lui répond. |
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A cubic polynomial |
2009-03-11 |
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Pedro pose la question :
I am having trouble figuring out the soultions for the polynomial equation
6x^3-17x^2+4x+12=0
Robert Dawson lui répond. |
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The angles of a triangle |
2009-03-11 |
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Marissa pose la question :
The angles in a triangle measure 7x-1, 18x+2, and 5x+10. Determine whether the
triangle is acute, obtuse, or right. State your reasons clearly.
Robert Dawson lui répond. |
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Area and perimeter |
2009-03-11 |
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Keith pose la question :
My question I thought was simple until I couldn’t find an answer anywhere. I have a shape with lots of different curves and some straight lines. I know how many feet the perimeter is and that’s it. How am I able to find the square footage of an area if all I know is its perimeter length?
Thank you,
Keith
Robert Dawson lui répond. |
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15 flavors of ice cream |
2009-03-11 |
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Pedro pose la question :
I was given this word question an was somewhat confused can u help me understand.
An ice cream vendor sells 15 flavors of ice cream and u want to sample at least
4 different types. how many different combinations of ice cream would u be able
to sample?
Penny Nom lui répond. |
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Marcia's summer earnings |
2009-03-11 |
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Yasmine pose la question :
Marcia saved money by working over the summer. Before school started, she spent 25%of the money of jewelry
and then 2/3 of the remaining money on a digital camera. She still had $213 left. How much money did she have
before she started shopping?
Robert Dawson and Penny Nom lui répond. |
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4 digit numbers from 1159 |
2009-03-10 |
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David pose la question :
I have the digits "1159" and need to come up with a complete list of possible four-digit combinations. It does NOT matter the order of the two number ones (1), so this will help eliminate many possibilities.
Separately, it would also help to actually know the actual number of combinations with which I am dealing to start.
David :)
Penny Nom lui répond. |
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Four digit numbers |
2009-03-10 |
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Theresa pose la question :
I need to know the number of 4 digit numbers that can be formed using 1-2-3-4 without repeating numbers
Penny Nom lui répond. |
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