New!
Get regular updates about newly solved problems
via algebra.com's RSS system.
Recent problems solved by 'edjones'
edjones answered: 7568 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649 , 1650..1679 , 1680..1709 , 1710..1739 , 1740..1769 , 1770..1799 , 1800..1829 , 1830..1859 , 1860..1889 , 1890..1919 , 1920..1949 , 1950..1979 , 1980..2009 , 2010..2039 , 2040..2069 , 2070..2099 , 2100..2129 , 2130..2159 , 2160..2189 , 2190..2219 , 2220..2249 , 2250..2279 , 2280..2309 , 2310..2339 , 2340..2369 , 2370..2399 , 2400..2429 , 2430..2459 , 2460..2489 , 2490..2519 , 2520..2549 , 2550..2579 , 2580..2609 , 2610..2639 , 2640..2669 , 2670..2699 , 2700..2729 , 2730..2759 , 2760..2789 , 2790..2819 , 2820..2849 , 2850..2879 , 2880..2909 , 2910..2939 , 2940..2969 , 2970..2999 , 3000..3029 , 3030..3059 , 3060..3089 , 3090..3119 , 3120..3149 , 3150..3179 , 3180..3209 , 3210..3239 , 3240..3269 , 3270..3299 , 3300..3329 , 3330..3359 , 3360..3389 , 3390..3419 , 3420..3449 , 3450..3479 , 3480..3509 , 3510..3539 , 3540..3569 , 3570..3599 , 3600..3629 , 3630..3659 , 3660..3689 , 3690..3719 , 3720..3749 , 3750..3779 , 3780..3809 , 3810..3839 , 3840..3869 , 3870..3899 , 3900..3929 , 3930..3959 , 3960..3989 , 3990..4019 , 4020..4049 , 4050..4079 , 4080..4109 , 4110..4139 , 4140..4169 , 4170..4199 , 4200..4229 , 4230..4259 , 4260..4289 , 4290..4319 , 4320..4349 , 4350..4379 , 4380..4409 , 4410..4439 , 4440..4469 , 4470..4499 , 4500..4529 , 4530..4559 , 4560..4589 , 4590..4619 , 4620..4649 , 4650..4679 , 4680..4709 , 4710..4739 , 4740..4769 , 4770..4799 , 4800..4829 , 4830..4859 , 4860..4889 , 4890..4919 , 4920..4949 , 4950..4979 , 4980..5009 , 5010..5039 , 5040..5069 , 5070..5099 , 5100..5129 , 5130..5159 , 5160..5189 , 5190..5219 , 5220..5249 , 5250..5279 , 5280..5309 , 5310..5339 , 5340..5369 , 5370..5399 , 5400..5429 , 5430..5459 , 5460..5489 , 5490..5519 , 5520..5549 , 5550..5579 , 5580..5609 , 5610..5639 , 5640..5669 , 5670..5699 , 5700..5729 , 5730..5759 , 5760..5789 , 5790..5819 , 5820..5849 , 5850..5879 , 5880..5909 , 5910..5939 , 5940..5969 , 5970..5999 , 6000..6029 , 6030..6059 , 6060..6089 , 6090..6119 , 6120..6149 , 6150..6179 , 6180..6209 , 6210..6239 , 6240..6269 , 6270..6299 , 6300..6329 , 6330..6359 , 6360..6389 , 6390..6419 , 6420..6449 , 6450..6479 , 6480..6509 , 6510..6539 , 6540..6569 , 6570..6599 , 6600..6629 , 6630..6659 , 6660..6689 , 6690..6719 , 6720..6749 , 6750..6779 , 6780..6809 , 6810..6839 , 6840..6869 , 6870..6899 , 6900..6929 , 6930..6959 , 6960..6989 , 6990..7019 , 7020..7049 , 7050..7079 , 7080..7109 , 7110..7139 , 7140..7169 , 7170..7199 , 7200..7229 , 7230..7259 , 7260..7289 , 7290..7319 , 7320..7349 , 7350..7379 , 7380..7409 , 7410..7439 , 7440..7469 , 7470..7499 , 7500..7529 , 7530..7559 , 7560..7589, >>NextProbability-and-statistics/472071: ?????
If one check in 10,000 is forged, 3% of all checks are postdated, and 70% of forged checks are postdated, find the probability that a postdated check is forged.(to five decimal places.)
1 solutions
Answer 323758 by edjones(7569)   on 2011-07-19 22:35:00 (Show Source):
You can put this solution on YOUR website!Out of 100,000 checks 10 are forged and 7 of the 10 are post dated.
Out of 100,000 checks 3,000 are post dated.
7/3000=.00233 the probability that a postdated check is forged.
.
Ed
|
Radicals/472087: the sqroot of (3x+10)^2= (5-2x)^2
1 solutions
Answer 323755 by edjones(7569) on 2011-07-19 22:22:43 (Show Source):
You can put this solution on YOUR website!3x+10=(5-2x)^2 remove the square sign from the left side.
...=4x^2-20x+25
4x^2-23x+15=0
4*15=60; The 2 factors of 60 whose sum is -23 are -3 and -20.
4x^2-3x-20x+15=0
x(4x-3)-5(4x-3)=0 factoring by grouping.
(x-5)(4x-3)=0
x=5, x=3/4
.
Ed
|
Probability-and-statistics/472094: The theoretical probability of undesirable side effects resulting from taking Grebex is 1 in 10. If 500 people take Grebex to lower their blood pressure, how many will encounter undesirable side effects?
1 solutions
Answer 323747 by edjones(7569) on 2011-07-19 22:10:30 (Show Source):
|
Probability-and-statistics/472133: The length x of the nails in a large shipment received by a carpenter are approximately normal with a mean of 2 inches and a standard deviation of .1 inches.
1) If a nail is randomly selected, find P (1.8 < x< 2.07)
2) The carpenter cannot use a nail shorter than 1.75 inches or longer than 2.25 inches. What percentage of the shipment of nails will the carpenter be able to use?
1 solutions
Answer 323745 by edjones(7569) on 2011-07-19 22:08:05 (Show Source):
|
Numeric_Fractions/472125: If 0 < x <1, then which of the following statements must be true?
I. (1/x)- x > 0
II. x^2 + x^2 < x
III. (x/sqrt(x)) < x^2
A) I only
B) II only
C) III only
D) I and II only
E) I and III only
Thanks!
1 solutions
Answer 323734 by edjones(7569) on 2011-07-19 21:39:56 (Show Source):
|
Probability-and-statistics/471644: 1) what are the odds aganist rolling a seven or a three with dice? please give solution
2) what is the probabilityof drawing a 2, a one eyed jack, or a sucide King from a standard deck of cards?
1 solutions
Answer 323465 by edjones(7569) on 2011-07-18 19:59:18 (Show Source):
|
Permutations/471631: A) If a club has 13 members, how many ways can a board of 3 officials can be chosen with individual mittens?
B) If 2 cards are drawn from a 52 card deck without replacing it, what is the probability of drawing a Jack and a 10?
C) Given a box with 2 purple, 6 red, and 9 green, what is the probability of randomly drawing a match?
D) A friend gave you 100 lottery tickets for your birthday. The probability of winning a prize is .012. What is the probability that you will have at least 2 winning tickets?
1 solutions
Answer 323463 by edjones(7569) on 2011-07-18 19:51:14 (Show Source):
You can put this solution on YOUR website!B) If 2 cards are drawn from a 52 card deck without replacing it, what is the probability of drawing a Jack and a 10?
.
There are 4 jacks and 4 tens.
(4C1*4C1)/52C2
=16/1326
=8/663
.
Ed
|
Functions/469722: How do I determine when I use this format for listing domain sets {x|-3 is lessthan or = to x is less than or =5} or list them out seperately {-3,-2,-1,0,1,2,3,4,5}
1 solutions
Answer 322249 by edjones(7569) on 2011-07-12 21:30:44 (Show Source):
|
Average/469739: A total of 50 juniors and seniors were given a mathematics test. The 35 juniors attained an average score of 80 while the 15 seniors attained an average of 70. What was the average score for all 50 students who took the test?
1 solutions
Answer 322245 by edjones(7569) on 2011-07-12 21:17:07 (Show Source):
|
Probability-and-statistics/469746: Assume a population with a mean of 136 and a standard deviation of 12.
A. Find the percentile rank of a score of 131.
a. 33.72%
b. 41.6%
c. 124%
d. 28.63%
B. Find the percentage of scores in between a score of 120 and a score of 140.
a. 20.00%
b. 40.82%
c. 53.75%
d. 13.33%
1 solutions
Answer 322242 by edjones(7569) on 2011-07-12 21:10:47 (Show Source):
|
Probability-and-statistics/469697: Can someone please help me. I need to know if the answer I have is correct.
The problem is, You can find the percentile that corresponds to a specific data value x by using the following formula.
Percentils of x = number of data values less than x divided by total number of data values times (100). There have been 75 winners for an acting award. Six winners were older than Jane Doe when they won the award. Find the percentile that corresponds to Jane Doe's age. Round to the nearest whole number as needed.
The answer I have is (71/75)*100=95. Is this correct?
Thanks
1 solutions
Answer 322241 by edjones(7569) on 2011-07-12 21:02:11 (Show Source):
You can put this solution on YOUR website!n=rank, N=number of values, P=percentile
n=P/100 * N + 1/2 Wikipedia
71=P/100 * 75 + 1/2
71=75P/100 + 1/2
75P/100=70.5
P=94
.
Ed
|
Probability-and-statistics/469719: Can soneone please let me know if I am on the right track with this problem, I may have figured the first part out, but I am stumped on the last parts.
The access code for a garage door consists of 3 digits. Each digit can be 0 through 7 and each digit can be repeated.
a)find the number of possible codes
b)What is the probability of randomly selecting the correct access code?
c)What is the probability of not selecting the correct access code?
The answer I have for the number of codes is: 290. I am stuck on the rest of the question, I need help. Thanks
1 solutions
Answer 322236 by edjones(7569) on 2011-07-12 19:51:33 (Show Source):
You can put this solution on YOUR website!a) 8^3=512
.
b) 1/512 the probability of selecting the correct access code on the first try.
.
c)511/512 the probability of not selecting the correct access code on the first try.
.
Ed
|
Probability-and-statistics/469701: Eighty percent of trees planted by a woodlands conservation group survive. What is the probability that:
a. 10 of the 12 trees just planted will survive?
b. at least 10 of the trees just planted will survive?
For part a, am I just suppose to multiply (.8) (10/12)?
I have no idea what to do for part b.
Thanks for your help.
1 solutions
Answer 322234 by edjones(7569) on 2011-07-12 19:45:31 (Show Source):
|
Probability-and-statistics/469617: Can a kind soul help me with my last killer homework problem? It states:
With probability 0.05 a robotic reporter that works for MEOW NEWS will make a false statement.
Suppose the reporter produced 1900 statements last week.
13. What is the probability that 85 or fewer of those statements were false? Round answer to four places after the decimal point.
P(0<= x <= 85) = binomcdf(1900,0.05,85) = 0.1586
but its wrong...
14. What is the probability that 124 or more of those statements were false? Round answer to four places after the decimal point.
P(124 <= x <= 1900) = 1 - binomcdf(1900,0.05,123) = 0.0019
also wrong... HELP!!!
1 solutions
Answer 322225 by edjones(7569) on 2011-07-12 19:29:22 (Show Source):
|
Average/469636: According to the Cable News Network (CNN), the number of injured in-line skaters (or “roller-bladers”) was 184% larger in 1994 than it was in 1993. Did the number of injured skaters almost double, almost triple, or more than triple?
1 solutions
Answer 322214 by edjones(7569) on 2011-07-12 16:40:17 (Show Source):
|
Probability-and-statistics/469642: Which pair has equally likely outcomes? List the letters of the two choices below which have equal probabilities of success, separated by a comma. A standard deck of cards has 12 face cards and four Aces (Aces are not face cards).
A. rolling a sum of 11 on two fair six sided dice
B. drawing a red nine out of a standard 52 card deck given it’s not a face card or an Ace.
C. rolling a sum of 10 on two fair six sided dice
D. rolling a sum of 7 on two fair six sided dice
E. drawing a six out of a standard 52 card deck given it’s not a face card or an Ace.
1 solutions
Answer 322213 by edjones(7569) on 2011-07-12 16:35:48 (Show Source):
|
Probability-and-statistics/469659: Each of the numbers 0 through 12 is written on a piece of paper and all of the pieces of paper are placed in a hat. One number is selected at random. Determine the probability that the number selected is even. Note: 0 is considered an even number.
7/13
1/2
7/12
6/13
1 solutions
Answer 322211 by edjones(7569) on 2011-07-12 16:28:11 (Show Source):
|
Probability-and-statistics/469654: An urn contains 8 red chips, 10 green chips, 2 white chips. A chip is drawn and replaced, and than a second chip drawn. what is the probability of
b. a white chip on the first and a red on the second?
c. two green chips being drawn?
d. a red chip on the second, given that a white chip was drawn on the first?
1 solutions
Answer 322207 by edjones(7569) on 2011-07-12 16:22:47 (Show Source):
|
Linear-equations/469652: My question says: Find an equation of the line having the specified slope and containing the indicated point. Write your answer in slope-intercept form.
m=-4;(-7,6) Can you show me the steps to slove this? Thanks
1 solutions
Answer 322203 by edjones(7569) on 2011-07-12 16:14:15 (Show Source):
|
Numbers_Word_Problems/469482: Problem: Twelve less than a number is the same as five times the number increased by four. Find the number.
The equation I came up with to solve this problem was 12 - x = 5(x +4). By writing my equation that way am I really saying "five times the SUM of a number and 4"? Instead, should the equation be 12 - x = 5x + 4, because the problem reads "fives times the number INCREASED by four"?
1 solutions
Answer 322103 by edjones(7569) on 2011-07-12 08:42:55 (Show Source):
|
Probability-and-statistics/469323: USA Today reports that about 25% of all prison parolees become repeat offenders. Alice is a social worker whose job is to counsel people on parole. Let us say success means a person does not become a repeat offender. Alice has been given a group of four parolees.
(a) Find the probability P(r) of r successes ranging from 0 to 4. (Round your answers to three decimal places.) P(0) = 1
P(1) =
P(2) =
P(3) =
P(4) =
(b) Make a histogram for the probability distribution of part (a).
1 solutions
Answer 322000 by edjones(7569) on 2011-07-11 19:55:30 (Show Source):
|
Quadratic-relations-and-conic-sections/469352: If the wheel is spun and each section is equally likely to stop under the pointer, determine the probability that the pointer lands on an even number, given that the color is red.
Wheel has 12 equal sections; 1 is blue, 2 is purple, 3 is tan, 4 is purple, 5-6-7 is red, 8 is blue, 9 is purple, 10 is tan, 11-12 is purple
1 solutions
Answer 321997 by edjones(7569) on 2011-07-11 19:48:26 (Show Source):
|
|
