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Probability-and-statistics/328413: Spacecraft are expected to land in a prescribed recovery zone 80% of the time. Over a period of time,six spacecraft land.
a)Find the probability that none lands in the prescribed zone.
b)Find the probability that at least one will land in the prescribed zone.
c)The landing program is called successful if the probability is 0.9 or more that three or more out of six spacecraft will land in the prescribed zone. Is the program successful? 1 solutions
Answer 235274 by Fombitz(13828) on 2010-08-03 14:10:42 (Show Source):
You can put this solution on YOUR website!a) P(none)= 
.
.
.
b)At least one means "not none".
P(not none)+P(none)= 
P(not none)=1-P(none)= 
.
.
.
c) Find P(3 or greater successes)=

P(>=3)= 
P(>=3)= 
Since  , success.
.
.
.
We could have also calculated,

and subtracted from 1

Same answer but saving one step.
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Probability-and-statistics/328408: A production line manufactures 5-gal(18.93-liter) gasoline cans to a volume tolerance of 5%. The probability of any one can being out of tolerance is 0.03. If 4 cans are selected at random:
a)What is the probability they are all out of tolerance?
b)What is the probability of exactly two being out?
c)What is the probability that all are in tolerance? 1 solutions
Answer 235267 by Fombitz(13828) on 2010-08-03 13:30:26 (Show Source):
You can put this solution on YOUR website!a) P(4 bad)= 
.
.
.
b) P(4 good)= 
Look at all of the possible combinations of exactly 2 bad (G-good, B-bad)
GGBB
GBGB
GBBG
BGGB
BGBG
BBGG
There are 6 of them.
Their individual probabilities are 
Since there are 6 of them,
P(exactly 2 bad)= 
.
.
.
c) P(4 good)=
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Systems-of-equations/328418: Can someone please walk me through this?
Solve the system of equations by substitution for real values of x and y.
x^2 + y^2 = 58
y = x^2 - 2
(_____,_____) (smaller x value)
(_____,_____) (larger x value)
Thank you,
Edgar 1 solutions
Answer 235263 by Fombitz(13828) on 2010-08-03 13:17:25 (Show Source):
You can put this solution on YOUR website!1. 
2.
From eq. 2,

Substitute into eq. 1,

Two solutions for y.

.
.
.

.
.
.Now solve for x.

.
.
.

No solution.
.
.
.
(-3,7) and (3,7) are the solutions
.
.
.
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Expressions-with-variables/328325: graph the line containing the given pair of points and find the slope
(3,0),(-1,-2) 1 solutions
Answer 235238 by Fombitz(13828) on 2010-08-03 10:36:12 (Show Source):
You can put this solution on YOUR website!Graph the points and draw the line between them,

.
.
.
You can read the slope from the line.
To go from one point to the other, move 4 units in the x, 2 units in the y.
Slope is change in y over change in x.

or you can solve it algebraically.

Then use the slope-intercept form of a line, 
Use either point to solve for  .
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Linear-equations/328392: In a shooting competition,a person receives $5 if he hits the mark and pays $2 if he misses it. He tried 60 shots and was paid $13. How many times did he hit the mark? 1 solutions
Answer 235235 by Fombitz(13828) on 2010-08-03 10:27:25 (Show Source):
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Travel_Word_Problems/328290: three times the number twice of blue marbles exceeds twice the number of red marbles by 18. Also 5 times the number of blue marbles if 2 less than 6 times the number of red marbles. how many of each are there? 1 solutions
Answer 235232 by Fombitz(13828) on 2010-08-03 10:22:10 (Show Source):
You can put this solution on YOUR website!Let B be the number of blue marbles, R red.
1. 
2. 
From eq. 1,

Substitute into eq. 2,

Multiply both sides by 15.

R is not an integer value which it must be.
Check the problem setup.
"three times the number twice of blue marbles"
Is this correct? Three times twice is 6 times.
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Linear-equations/328402: Without graphing, determine whether the following paraholas opens upward or
downward and find the vertex.
g(x)=-4(x+1)^2+8
I know it opens downward and the vertex is (-1,8) I just don't know how it was
found. Can you please help.
Thanks 1 solutions
Answer 235228 by Fombitz(13828) on 2010-08-03 10:11:34 (Show Source):
You can put this solution on YOUR website!DUPLICATE
Previously answered See Answer 235190.
It opens downward because the  coefficient is negative (-4).
.
.
.
It's in vertex form  where (h,k) is the vertex.
If the parabola opens upwards, the vertex y coordinate is the minimum y value.
If the parabola opens downwards, the vertex y coordinate is the maximum y value.
In this case, 
.
.
.
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Linear-equations/328380: In a shooting competition, a person receives $5 if he hits the mark and pays $2 if he misses it.He tried 60 shots and was paid $13. how many times did he hit the mark? 1 solutions
Answer 235226 by Fombitz(13828) on 2010-08-03 10:08:54 (Show Source):
You can put this solution on YOUR website!Let H be the number of hits, M the number of misses.
1. 
2. 
Multiply eq. 1 by 2 and add to eq. 2 to eliminate M.

Then from eq. 1,

.
.
.
19 hits and 41 misses.
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Linear-systems/328327: how do you graph this?
-3x+6y=36
-x+2y=-8 1 solutions
Answer 235223 by Fombitz(13828) on 2010-08-03 09:56:22 (Show Source):
You can put this solution on YOUR website!Find the x and y intercepts.
To find the x-intercept, set y=0 and solve for x.

(-12,0)
To find the y-intercept, set x=0 and solve for y.

(0,6)
Plot the points and connect them with a line.
.
.
.

.
.
.
-x+2y=-8
Find the x and y intercepts.
To find the x-intercept, set y=0 and solve for x.

(8,0)
To find the y-intercept, set x=0 and solve for y.

(0,-4)
Plot the points and connect them with a line.
.
.
.
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Mixture_Word_Problems/328385: a long distance trucker travled 220 miles in one direction during a snow storm. The return trip in a rainy weather was accomplished at doubled the speed and took 5 hours less time. find the speed going. 1 solutions
Answer 235219 by Fombitz(13828) on 2010-08-03 09:40:02 (Show Source):
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Graphs/328388: Good morning,
Here is my question
What is the relationship of the lines which have equations of y=2 and x=0
A. Parallel
B. Perpendicular
C. Intersecting
D. Not enough info to tell
I know y=2 will create a horizontal on the y-axis at point 2. And I know 0 can't be plotted. Yet the question is so tricky I'm sure it can't just be D.
Any help is welcome
Thank you very much! 1 solutions
Answer 235217 by Fombitz(13828) on 2010-08-03 09:33:38 (Show Source):
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Expressions-with-variables/328316: 9x-8y=32
8y-9x=-32
what is the solution of the system equations
a no solution
b infinitely many solution
c a point
is the system consistent or inconsistent
is the system dependent or independent 1 solutions
Answer 235216 by Fombitz(13828) on 2010-08-03 09:32:03 (Show Source):
You can put this solution on YOUR website!1. 
.
.
.

2. 
.
.
.
Eq.2 is eq.1 multiplied by (-1), they are the same line.
This a dependent, consistent system with infinitely many solutions.
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