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Thank you 1 solutions
Answer 27070 by fractalier(2101) on 2006-06-13 11:37:46 (Show Source):
You can put this solution on YOUR website!You divide 972 by 4096 and then take the fifth root to find the common ratio r...since you need four intermediate geometric means, there will be five increments...when you do that you find that r = 3/4...so that your sequence looks like...
4096, 3072, 2304, 1728, 1296, 972
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Graphs/41857: find the slopes, if they exist, of the linecontaining these points?
(-5,4)and(1-2)
(3,2)and(-5,0) 1 solutions
Answer 27059 by fractalier(2101) on 2006-06-13 11:03:40 (Show Source):
You can put this solution on YOUR website!Slope m is found by the formula
m = (y2 - y1) / (x2 - x1)
So for (-5,4) and (1,-2), we have
m = (-2 - 4) / (1 -(-5)) =
m = -6 / 6 = -1
And for (3,2) and (-5,0), we have
m = (0 - 2) / (-5 - 3) =
m = -2 / -8
m = 1/4
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Linear-equations/41928: what does the equation y=mx+c mean? 1 solutions
Answer 27058 by fractalier(2101) on 2006-06-13 11:01:00 (Show Source):
You can put this solution on YOUR website!This is a linear function showing a relationship between x and y.
For y = mx + c, we have y expressed as a function of x, whereby any increase in x is calculated to be an (m times x) increase in y. The c value is the value of y when x = 0.
If this function is graphed as a line, m is the slope of that line and c is the y-intercept.
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Probability-and-statistics/41886: The time a group of high school students arrive home from school each day was found to be normally distributed. The mean time was 3:15 PM and the times had a standard deviation of 15 minutes. What is the probability that a student chosen at random arrives home from school before 2:30 PM? 1 solutions
Answer 27056 by fractalier(2101) on 2006-06-13 10:58:09 (Show Source):
You can put this solution on YOUR website!Well 2:30 pm represents three sigmas below the mean...so look up on your normal distribution table a z-score of -3.00 and find the probability of .0013.
Thus the probability is .13% that a student chosen at random arrives before 2:30 pm.
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Equations/41890: Find the equation of the line containing the point (-1,3) and perpendicular to hte line 2x+4y=-1 1 solutions
Answer 27054 by fractalier(2101) on 2006-06-13 10:54:51 (Show Source):
You can put this solution on YOUR website!We need a line perpendicular to
2x + 4y = -1
Let us find the slope of this line first...
4y = -2x - 1
y = (-1/2)x - 1/4
The slope here is -1/2.
The slope of the perpendicular to it is the negative reciprocal, or +2.
Now use the point-slope form
y - y1 = m(x - x1)
y - 3 = 2(x + 1)
y - 3 = 2x + 2
y = 2x + 5
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Surface-area/41925: Question
As many 8-cm diameter discs as possible are cut from a sheet of rectangular cardboard measuring 170 cm by 90 cm. Find the area of the sheet that is left.
Please help to solve this question.
Thank you very much. 1 solutions
Answer 27049 by fractalier(2101) on 2006-06-13 10:36:24 (Show Source):
You can put this solution on YOUR website!Well 21 discs one way and 11 disks the other way can be cut...231 disks in total...let's find thier total area and subtract it from the area of the original sheet...
A = 231 * ((pi)r^2)
A = 231 * 16pi
A = 3696*pi sq cm
The original sheet was 90 x 170 or 15300 sq cm.
Now subtract to get the leftover area
Leftover = 15300 - 3696(pi) or about 3689 sq cm
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Polynomials-and-rational-expressions/41867: This question is from textbook
A plane flies 720 mi against a steady 30-mi/h headwind and then returns to the same point with the wind. If the entire trip takes 10 h, what is the plane's speed in still air?
Thanks! 1 solutions
Answer 27046 by fractalier(2101) on 2006-06-13 10:25:01 (Show Source):
You can put this solution on YOUR website!In problems like this, we always use distance = rate * time, or D = RT.
Thus T = D/R. Let R be the plane's speed in still air.
Going against the wind, we have
T1 = 720 / (R - 30) and
T2 = 720 / (R + 30)
But these two times add to 10 hours, so we have
720 / (R - 30) + 720 / (R + 30) = 10
Now multiply everything by (R+30)(R-30) to clear fractions...
720(R+30) + 720(R-30) = 10(R+30)(R-30)
Now solve for R...
720R + 21600 + 720R - 21600 = 10(R^2 - 900)
1440R = 10(R^2 - 900)
144R = R^2 - 900
R^2 - 144R - 900 = 0
(R - 150)(R + 6) = 0
R = 150 mph
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Probability-and-statistics/41881: Two cards are drawn from a standard deck of cards. Find the probability that a king or a red card is drawn. 1 solutions
Answer 27045 by fractalier(2101) on 2006-06-13 10:15:21 (Show Source):
You can put this solution on YOUR website!Since the question is an OR case, we add the probabilities...
The probability of picking a king is 4/52 or 1/13 and
the probability of picking a red card is 26/52 or 1/2, we add
1/13 + 1/2 =
2/26 + 13/26 =
15/26
Thus 15/26 is the probability of any one card be a king or red.
To do it twice (after first replacing the card), one would then multiply
15/26 by itself, giving us 225/676.
To do it in either card, we add 15/26 + 15/26 = 15/13...or a certainty...
It is not clear how we draw the two cards.
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Equations/41869: What is the value of the discriminant?
X(squared) - 3x - 12 = 0
The teacher collected the textbooks today, the final is tomorrow. 1 solutions
Answer 27044 by fractalier(2101) on 2006-06-13 10:11:06 (Show Source):
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Age_Word_Problems/41901: Hello!
Can somebody help please?
My question is:
Last time it was the kids birthdays I noticed that even though they were born only one year apart, when I squared their ages and then added the sum of the ages they would total 1105. How old are my kids?
Thanks. Your help and time are much appreciated.
marangeo 1 solutions
Answer 27042 by fractalier(2101) on 2006-06-13 10:05:50 (Show Source):
You can put this solution on YOUR website!Okay let their ages be x and x+1, since they are a year apart. Then we have
x^2 + (x+1)^2 + x + x+1 = 1105
Now solve this...
x^2 + x^2 + 2x + 1 + x + x + 1 = 1105
2x^2 + 4x + 2 = 1105
2x^2 + 4x - 1103 = 0
This is not factorable, so we use the quadratic formula to get
x = (-4 ± sqrt(16 + 8824)) / 4
x = (-4 ± sqrt(8840)) / 4
x = (-4 ± 2*sqrt(2210)) / 4
x = (-2 ± sqrt(2210)) / 2
x is about 22.5 years old
x+1 is about 23.5 years old
I have a feeling there is something wrong with the problem...
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Sequences-and-series/41805: A scout troop will prepare trail mix for their next hike. They have decided to mix one type of nut, one type of dried fruit, and one type of granola. The local store carries 8 types of nuts, 6 types of dried fruit, and 5 types of granola. How many different trail mixes are possible?
Thanks 1 solutions
Answer 26971 by fractalier(2101) on 2006-06-12 12:17:07 (Show Source):
You can put this solution on YOUR website!For every nut type, we have 6 fruit and 5 granola...thus 30 for each nut type and there are 8 nut types, so the answer turns out to be
8 * 6 * 5 =
240 mixes
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Probability-and-statistics/41810: From a group of 6 men and 4 women, a committee of 3 is to be selected at random. Find P(at least 2 women). 1 solutions
Answer 26970 by fractalier(2101) on 2006-06-12 12:12:26 (Show Source):
You can put this solution on YOUR website!We can add up the possibilities...
start with having all three women...how many ways can we choose that?
Well 4 chosen three at a time is C(4,3) = 4 ways
Now, let's look at just two women...how many ways can we choose them? Well, C(4,2) = 6 ways...but for each of these ways, we can have any of six men, so there's a total of 36 ways this can happen...
Thus the grand total is 40 different ways.
Let me complete the problem...
How many total ways are there altogether? Well if we complete the ananlysis by looking at C(4,1)*C(6,2), we get
4*15 = 60 one woman committees and
C(6,3) = 20 no woman committees,
so there are a grand total of 120 possible committees, and thus
P(at least two women) = 40/120 = 1/3
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Probability-and-statistics/41809: A red and a blue die are tossed. What is the probability that the red die shows an odd number and the blue die shows a 1 or 2? Thanks 1 solutions
Answer 26969 by fractalier(2101) on 2006-06-12 12:09:07 (Show Source):
You can put this solution on YOUR website!Assuming fair six-sided dice, we multiply the individual probabilities because we are asked to find the AND case...
so we have a 3 out of 6 for an odd on the red and
we have a 2 out of 6 for a 1 or a 2 on the blue...
multiplying we get
3/6 * 2/6 = 6/36 =
1/6
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