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edjones answered: 7568 problems
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Numbers_Word_Problems/468091: A number is decreased by 11, and the result it multipled by 2. the final answer is 20. What is the number? 1 solutions Answer 321164 by edjones(7569)   on 2011-07-07 15:33:22 (Show Source): You can put this solution on YOUR website! 2(x-11)=20 2x-22=20 2x=42 x=21 . Ed

Numbers_Word_Problems/468092: What is the greater common factor of 18, 54, and 90? 1 solutions Answer 321163 by edjones(7569)   on 2011-07-07 15:31:45 (Show Source): You can put this solution on YOUR website! 18

Angles/468080: Which of these angles are complementary?A. 45o and 45o B. 63o and 117o C. 45o and 135o D. 90o and 45o 1 solutions Answer 321161 by edjones(7569)   on 2011-07-07 15:29:58 (Show Source): You can put this solution on YOUR website! A

Age_Word_Problems/467995: Sarah is now 3 years older than kevin. 5 years from now she will be 1.25 times as old as Kevin. how old are they now 1 solutions Answer 321160 by edjones(7569)   on 2011-07-07 15:28:43 (Show Source): You can put this solution on YOUR website! s=sarah's age, k=kevin's age s=k+3 s+5=1.25(k+5) k+3+5=1.25(k+5)Substitute k+3 for s k+8=1.25k+6.25 -.25k=-1.75 k=7 s=10 . Ed

Equations/468087: in a certain survey of 1,004 adults, 83% reported having more than one television at home. Find the actual number of respondents corresponding to the given percentage? 1 solutions Answer 321157 by edjones(7569)   on 2011-07-07 15:17:48 (Show Source): You can put this solution on YOUR website! 1004*.83=833.32

Numbers_Word_Problems/468088: five times the difference of twice a number and six is negative twenty. Find the numbers. 1st number= x 2nd number= 5(2x-6) x+5(2x-6)= -20 1 solutions Answer 321156 by edjones(7569)   on 2011-07-07 15:16:14 (Show Source): You can put this solution on YOUR website! 5(2x-6)=-20 10x-30=-20 10x=10 x=1 . Ed

Probability-and-statistics/468072: one card is selected at random from a deck of cards. Determine the probability that the card selected is a 5 or a 7 1 solutions Answer 321154 by edjones(7569)   on 2011-07-07 15:12:52 (Show Source): You can put this solution on YOUR website! In a 52 card deck there are 4 fives and 4 sevens. 4+4=8 8/52=2/13 the probability that the card selected is a 5 or a 7. . Ed

absolute-value/468041: |x^2-3x+3|=3 1 solutions Answer 321153 by edjones(7569)   on 2011-07-07 15:10:11 (Show Source): You can put this solution on YOUR website! |x^2-3x+3|=3 x^2-3x+3=3 x^2-3x=0 x(x-3)=0 x=3, x=0 . -(x^2-3x+3)=3 -x^2+3x-3=3 x^2-3x+3=-3 x^2-3x+6=0 There is no real answer for x . x=3, x=0 are the only answers. . Ed

Probability-and-statistics/468077: From 20 tickets marked with the first 20 numerals, one is drawn at random. What is the chance that it will be a multiple of 3 or of 7? 1 solutions Answer 321150 by edjones(7569)   on 2011-07-07 14:46:16 (Show Source): You can put this solution on YOUR website! There are 6 multiples of three and 2 multiples of seven. 6+2=8 8/20=2/5 the chance that it will be a multiple of 3 or of 7. . Ed

Polynomials-and-rational-expressions/468074: Hello. Can you please help me? I need to make v the subject of the following formula : 1/f = 1/u + 1/v ?? Thank you! 1 solutions Answer 321149 by edjones(7569)   on 2011-07-07 14:39:54 (Show Source): You can put this solution on YOUR website! Solve for v: 1/f = 1/u + 1/v vu=vf+uf multiply each side by fuv vu-vf=uf v(u-f)=uf v=uf/(u-f) . Ed

Probability-and-statistics/468063: I would highly appreciate assistance from a tutor on how to do these three difficult homework problems that are due tonight. I don't know if I am solving them correctly. Please show me if I am mislead. 4. (1 point) Suppose in a village 50% of the people farm, 60% of the people fish, and 70% of the people either farm or fish. What is the percentage of people in the village who both farm and fish? .5+.6= 1.1 - .7 = .4? 5. (1 point) Suppose in a village 50% of the people farm, 60% of the people fish, and 70% of the people either farm or fish. If a randomly chosen person farms, what is the probability that this person also fishes? .5 x .6= .3? 6. (1 point) Suppose 48% of a village’s population is male. 30% of the men smoke, 20% of the women smoke. If a randomly chosen person is found to be a smoker, what is the probability that this person is a man? Round answer to two places after the decimal point. .48 x .3 = .144= .14? 1 solutions Answer 321146 by edjones(7569)   on 2011-07-07 14:31:11 (Show Source): You can put this solution on YOUR website! This is very easy once you understand Venn diagrams. Let x=the intersection of farm and fish: .5-x+.6-x+x=.7 the union of farm and fish. 4)1.1-x=.7 x=.4 answer farm only = .1 fish only = .2 . 5).4/.5=.8 . 6) .48*.3=.144 male smokers .52*.2=.104 female smokers --------------add ======>.248 . .144/.248 = .58 probability the this person is a man. . Ed

Probability-and-statistics/466654: I have worked this one out but I am not sure if the answer is correct. I only get one shot so any assistance helps. A fair coin is flipped 20 times and the sequence of heads and tails is observed. Find the probability that the sequence consists of AT LEAST two heads. Answer in fraction reduced to the lowest terms. i said: 1048555/1048576 Refer to the given graph. Assume one can move only down or to the right. If a route starts at A and ends at C, what is the probability that the route passes through B? Answer in fraction reduced to the lowest terms. a [][][]b[][] [][][][][] [][][][][] [][][][][] [][][][][]c I said c(4,1) but that isn't what it's asking for. Do i need to multiply C(4,1) by c(10,5) to find the probability of passing through b? 1 solutions Answer 320216 by edjones(7569)   on 2011-07-03 22:02:04 (Show Source): You can put this solution on YOUR website! Your first answer is correct. . Ed

Probability-and-statistics/465878: What is the probability that 6 rolls of a fair die will show four exactly 2 times? According to a college survey 22% of all students work fulltime. Find the mean for the random variable x the number of students who work full time in the sample is 16. 1 solutions Answer 319274 by edjones(7569)   on 2011-06-29 23:37:12 (Show Source): You can put this solution on YOUR website! b) mean(x) =np =16*.22 =3.52 . Ed

Finance/465872: I really need some help here getting started...I do not know what I am suppose to do and there are many parts to this but a,b are the key questions I need help with because the other questions work off this. a. Suppose a market research company finds that at a price of p = $10, they would sell x = 24 tiles each month. If they lower the price to p = $5, then more people would purchase the tile, and they can expect to sell x = 44 tiles in a month’s time. Find the equation of the line for the demand equation. Write your answer in the form p = mx + b. Hint: Write an equation using two points in the form (x,p) and remember that order matters! b. Substitute the result you found from part a. into the equation R = xp to find the revenue equation. Provide your answer in simplified form. 1 solutions Answer 319273 by edjones(7569)   on 2011-06-29 23:26:57 (Show Source): You can put this solution on YOUR website! (24,10) & (44,5) . (p-p1)/(x-x1)=m m=(5-10)/(44-24) =-5/20 =-1/4=-.25 slope . (p-p1)=m(x-x1) p-10=-.25(x-24) p-10=-.25x+6 p=-.25x+16 . R=xp =x(-.25x+16) =-.25x^2+16x . Ed

Word_Problems_With_Coins/465770: A sum of money amounts to 9.20 pesos,is made up of 10Centavos and 25Centavos coins. If there are 8 more than coins in 10Centavos than 25Centavos. How many coins each kind are there? 1 solutions Answer 319258 by edjones(7569)   on 2011-06-29 21:49:35 (Show Source): You can put this solution on YOUR website! Let t=the number of 10c coins and f=the number of 25c coins t=f+8 .1(f+8)+.25f=9.2 .1f+.8+.25f=9.2 .35f=8.4 f=24 t=32 . Ed

Permutations/465776: 1. How many garlands can be made from 6 marigolds and 2 roses? 2. How many ways can a necklace be formed from 2 red and 2 blue beads? 1 solutions Answer 319254 by edjones(7569)   on 2011-06-29 21:37:07 (Show Source): You can put this solution on YOUR website! 2) 4!/2!*2!=6 . Ed

Travel_Word_Problems/465778: a train traveling at 55 km per hour has to make a trip of 100 miles. how many minutes will it take for the train to make the trip? 1 solutions Answer 319251 by edjones(7569)   on 2011-06-29 21:32:06 (Show Source): You can put this solution on YOUR website! speed * time = distance 55*t=100 t=100/55 =20/11 hrs. . Ed

Evaluation_Word_Problems/465782: A stock decreases in value by 20 percent. By whay percent must the stock reach its former value. A. 15% B.20% C. 25% D. 40% 1 solutions Answer 319250 by edjones(7569)   on 2011-06-29 21:28:17 (Show Source): You can put this solution on YOUR website! 20/100=.2=20% 100/80=1.25=125% C . Ed

Probability-and-statistics/465834: Find the area under the standard normal curve for the following: (A) P(z > 1.98) (B) P(-1.93 < z < 0) (C) P(-0.67 < z < 0.77) 1 solutions Answer 319247 by edjones(7569)   on 2011-06-29 21:21:50 (Show Source): You can put this solution on YOUR website! a) .0239 . b).4731 . c).5279 . Ed

Probability-and-statistics/465515: A sample of 400 racing cars showed that 80 cars cost over $700,000. What is the 99% confidence interval of the true proportion of cars costing over $700,000? 1 solutions Answer 319016 by edjones(7569)   on 2011-06-28 23:05:28 (Show Source): You can put this solution on YOUR website! , q=0.8, n=400 (a,b)= *=.2+-(2.576*.02)=(.1485, .2515) We can say with 99% confidence that the proportion of cars costing over $700,000 is in the interval (.1485, .2515). . Ed

Evaluation_Word_Problems/465513: For borrowers with good credit scores, the mean debt for revolving and installment accounts is $15,015 (BusinessWeek, March 20, 2006). Assume the standard deviation is $3,650 and that debt amounts are normally distributed. What is the probability that the debt for a randomly selected borrower with good credit is more than $18,000 (to 4 decimals)? What is the probability that the debt for a randomly selected borrower with good credit is less than $10,000 (to 4 decimals)? What is the probability that the debt for a randomly selected borrower with good credit is between $12,000 and $18,000 (to 4 decimals)? What is the probability that the debt for a randomly selected borrower with good credit is no more than $14,000 (to 4 decimals)? 1 solutions Answer 319010 by edjones(7569)   on 2011-06-28 22:24:45 (Show Source): You can put this solution on YOUR website! What is the probability that the debt for a randomly selected borrower with good credit is between $12,000 and $18,000 (to 4 decimals)? z=(12000-15015)/3650 = -.8260 z=(18000-15015)/3650 = .8178 The area under the normal curve between -.8260 and .8178 is .5889 the probability that the debt for a randomly selected borrower with good credit is between $12,000 and $18,000 . Ed

Probability-and-statistics/465440: According to the Sleep Foundation, the average night's sleep is 6.8 hours (Fortune, March 20, 2006). Assume the standard deviation is .7 hours and that the probability distribution is normal. What is the probability that a randomly selected person sleeps more than 8 hours (to 4 decimals)? What is the probability that a randomly selected person sleeps 6 hours or less (to 4 decimals)? Doctors suggest getting between 7 and 9 hours of sleep each night. What percentage of the population gets this much sleep (to the nearest whole number)? % 1 solutions Answer 319007 by edjones(7569)   on 2011-06-28 22:15:45 (Show Source): You can put this solution on YOUR website! z=(8-6.8)/.7=1.714 Area under normal curve above 1.714 is .0433 the probability that a randomly selected person sleeps more than 8 hours. . Ed

Probability-and-statistics/465510: A study found that the average life expectancy is 53 years with a standard deviation of 7.5 years. If a person is selected at random, what is the probability that the person will die before the age of 65? A. 94.52% B. 82.89% C. 94.95% D. 88.49% 1 solutions Answer 319004 by edjones(7569)   on 2011-06-28 22:07:34 (Show Source): You can put this solution on YOUR website! z=(65-53)/7.5=1.6 The area under the normal curve below 1.6 is .9452=94.52% . Ed

Evaluation_Word_Problems/465438: For borrowers with good credit scores, the mean debt for revolving and installment accounts is $15,015 (BusinessWeek, March 20, 2006). Assume the standard deviation is $3,380 and that debt amounts are normally distributed. What is the probability that the debt for a randomly selected borrower with good credit is more than $18,000 (to 4 decimals)? What is the probability that the debt for a randomly selected borrower with good credit is less than $10,000 (to 4 decimals)? What is the probability that the debt for a randomly selected borrower with good credit is between $12,000 and $18,000 (to 4 decimals)? What is the probability that the debt for a randomly selected borrower with good credit is no more than $14,000 (to 4 decimals)? 1 solutions Answer 319003 by edjones(7569)   on 2011-06-28 22:02:25 (Show Source): You can put this solution on YOUR website! z=(18000-15015)/3380=.8831 area under normal curve above z=.8831 is .1886 the probability that the debt for a randomly selected borrower with good credit is more than $18,000. . Ed

Miscellaneous_Word_Problems/465476: -5/6 x (-8/5)= 1 solutions Answer 319001 by edjones(7569)   on 2011-06-28 21:54:33 (Show Source): You can put this solution on YOUR website! -5/6 * -8/5=40/30=4/3

test/465463: solve each system by eliminatiom. problem: 2x + 3y = 5 and 2x + 2y = 8 1 solutions Answer 318999 by edjones(7569)   on 2011-06-28 21:52:01 (Show Source): You can put this solution on YOUR website! 2x + 3y = 5 2x + 2y = 8 -------------subtract y=-3 . x=7 . Ed

Probability-and-statistics/465475: SAT verbal scores are normally distributed with a mean of 430 and a standard deviation of 120 If 1 of the student is randomly selected, find the probability that he or she obtained a score higher than 440. 1 solutions Answer 318996 by edjones(7569)   on 2011-06-28 21:45:27 (Show Source): You can put this solution on YOUR website! z=(440-430)/120=.083 The area under the normal curve above z=.083 is .467 the probability that he or she obtained a score higher than 440. . Ed

Probability-and-statistics/465499: I'm stuck on this :/ some one please help SAT verbal scores are normally distributed with a mean of 430 and a standard deviation of 120 If 1 of the student is randomly selected, find the probability that he or she obtained a score higher than 440. 1 solutions Answer 318991 by edjones(7569)   on 2011-06-28 21:26:14 (Show Source): You can put this solution on YOUR website! z=(440-430)/120=.083 The area under the normal curve above z=.083 is .467 the probability that he or she obtained a score higher than 440. . Ed

Angles/465484: find the complementary angle of 84 degrees 1 solutions Answer 318987 by edjones(7569)   on 2011-06-28 21:21:41 (Show Source): You can put this solution on YOUR website! 90-84=6 degrees

Age_Word_Problems/465487: rose is 2 cm taller than joan.Let r=roses height.then ? = joans height? 1 solutions Answer 318986 by edjones(7569)   on 2011-06-28 21:18:27 (Show Source): You can put this solution on YOUR website! joans height = r-2

Permutations/465104: Find the indicated probability. Express your answer as a simplified fraction unless otherwise noted. The following table contains data from a study of two airlines which fly to Small Town, USA. # on time # late Poduck airlines 33 6 Upstate Airlines 43 5 If one of the 87 flights is randomly selected, find the probability that the flight selected arrived on time given that it was an Upstate Airlines flight 1 solutions Answer 318733 by edjones(7569)   on 2011-06-28 03:23:56 (Show Source): You can put this solution on YOUR website! 43+5=48 43/48 the probability that the flight selected arrived on time given that it was an Upstate Airlines flight. . Ed