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A normal distribution problem |
2009-03-13 |
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From jude:
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.
Answered by Robert Dawson. |
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Probability |
2009-03-12 |
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From jude:
) 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?
Answered by Robert Dawson. |
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Stacking eggs |
2009-03-12 |
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From Prashanth:
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
Answered by Robert Dawson. |
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A regular decagon is inscribed in a circle |
2009-03-12 |
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From Renata:
A regular decagon is inscribed in a circle of diameter 36 feet. Approximate the perimeter and area of the decagon.
Answered by Robert Dawson. |
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Three consecutive odd integers |
2009-03-11 |
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From Susan:
Find three consecutive odd integers such that the sum of the first, twice the second, and three times the third is 70
Answered by Penny Nom. |
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Water drains from a conical tank |
2009-03-11 |
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From Tyler:
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.
Answered by Penny Nom. |
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The equation of a line |
2009-03-11 |
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From Teresa:
Write an equation in slope-intercept form that has a horizontal intercept of -7/3 and a vertical intercept of -7/9
Answered by Harley Weston. |
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A sequence |
2009-03-11 |
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From Vly:
2; 6; 26;126;626 find the nth term
Answered by Harley Weston. |
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A cubic polynomial |
2009-03-11 |
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From Pedro:
I am having trouble figuring out the soultions for the polynomial equation
6x^3-17x^2+4x+12=0
Answered by Robert Dawson. |
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The angles of a triangle |
2009-03-11 |
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From Marissa:
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.
Answered by Robert Dawson. |
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Area and perimeter |
2009-03-11 |
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From Keith:
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
Answered by Robert Dawson. |
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15 flavors of ice cream |
2009-03-11 |
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From Pedro:
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?
Answered by Penny Nom. |
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Marcia's summer earnings |
2009-03-11 |
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From Yasmine:
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?
Answered by Robert Dawson and Penny Nom. |
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4 digit numbers from 1159 |
2009-03-10 |
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From David:
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 :)
Answered by Penny Nom. |
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Four digit numbers |
2009-03-10 |
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From Theresa:
I need to know the number of 4 digit numbers that can be formed using 1-2-3-4 without repeating numbers
Answered by Penny Nom. |
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