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# Recent problems solved by 'ewatrrr'

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 absolute-value/618379: [x-11]=141 solutions Answer 388840 by ewatrrr(10682)   on 2012-06-06 10:06:25 (Show Source): You can put this solution on YOUR website! ``` Hi, Assuming Absolute Value of (x-11) |x-11| = 14 x-11 = 14 x-11 = -14 ```
 Inequalities/618377: Please solve & show work for: y>-3 x<2 line under < sign Name a point for y>-3 Name a point for x< 2 with line under < Name a point for both. Please help. I paid \$5.00 thru the math tutor website & never receive an answer. this is my last problem to do. Thank you Lynnette Custer lynnbuz@yahoo.com1 solutions Answer 388839 by ewatrrr(10682)   on 2012-06-06 10:02:51 (Show Source): You can put this solution on YOUR website! ``` Hi, y >-3 and x ≤2 Name a point for y>-3 pt(0,-2) Pt(3,-2) All Pts above the Green Line Name a point for x ≤2 Pt(1,-4) All Pts to the Left of the Blue Line Name a point for both. (1,-2) ```
 logarithm/618366: The question is asking me to convert the following into a single logarithm: – They want me to show them the steps. Any help would be greatly appreciated. 1 solutions Answer 388835 by ewatrrr(10682)   on 2012-06-06 09:23:56 (Show Source): You can put this solution on YOUR website! ``` Hi, – – – ```
 Probability-and-statistics/618318: A normal population has μ = 30 and σ = 7. For a random sample of size n = 6, determine the mean of X and standard deviation of X.1 solutions Answer 388834 by ewatrrr(10682)   on 2012-06-06 09:14:32 (Show Source): You can put this solution on YOUR website! ``` Hi, normal population has μ = 30 and σ = 7. determine the mean of X and standard deviation of X. random sample of size n = 6 X = 30 s = ```
 Travel_Word_Problems/618348: While driving 90km/h how far can you travel in 3.5 hrs ?1 solutions Answer 388827 by ewatrrr(10682)   on 2012-06-06 08:38:50 (Show Source): You can put this solution on YOUR website! ``` Hi, While driving 90km/h how far can you travel in 3.5 hrs ? Note: D = rt ```
 Triangles/618352: A triangle has side lengths of 5, 9 and 12. Is it right acute or obtuse?1 solutions Answer 388823 by ewatrrr(10682)   on 2012-06-06 08:34:08 (Show Source): You can put this solution on YOUR website!``` Hi, A triangle has side lengths of , and . Is it right acute or obtuse? Doing the Squares Testing: |||Obtuse Triangle ***If is true, then we have a right triangle ***If is the case, then we have an acute triangle. ***If , then we have an obtuse triangle. ```
 Permutations/618333: Last year, the personal best high jumps of track athletes in a nearby state were normally distributed with a mean o 205 cm and a standard deviation of 13 cm. What is the probability that a randomly selected high jumper has a personal best between 205 and 231 cm?1 solutions Answer 388821 by ewatrrr(10682)   on 2012-06-06 08:25:34 (Show Source): You can put this solution on YOUR website! ``` Hi, Previously Posted Last year, the personal best high jumps of track athletes in a nearby state were normally distributed with a mean of 205 cm and a standard deviation ofcm. P(205< X <231) = For the normal distribution: one standard deviation from the mean accounts for about 68.2% of the set standard deviations from the mean account for about 95.4% and three standard deviations from the mean account for about 99.7%. ```
 Probability-and-statistics/618340: Suppose we have a set of body temperatures with a mean of 98.6 degrees, and a sample standard deviation of 0.5 degrees. If we assume a normal distribution of body temperatures in the larger population, between what two values should 99.7% of all temperatures lie? 1 solutions Answer 388820 by ewatrrr(10682)   on 2012-06-06 08:01:34 (Show Source): You can put this solution on YOUR website! ``` Hi, body temperatures with a mean of 98.6 degrees, and a sample standard deviation of 0.5 degrees what two values should 99.7% of all temperatures lie? Within SD of the mean: For the normal distribution: one standard deviation from the mean accounts for about 68.2% of the set two standard deviations from the mean account for about 95.4% and three standard deviations from the mean account for about 99.7%. ```
 Permutations/618325: Last year, the personal best high jumps of track athletes in a nearby state were normally distributed with a mean of 205 cm and a standard deviation of 13 cm. What is the probability that a randomly selected high jumper has a personal best between 205 and 231 cm?1 solutions Answer 388819 by ewatrrr(10682)   on 2012-06-06 07:23:26 (Show Source): You can put this solution on YOUR website! ``` Hi, Last year, the personal best high jumps of track athletes in a nearby state were normally distributed with a mean of 205 cm and a standard deviation ofcm. P(205< X <231) = For the normal distribution: one standard deviation from the mean accounts for about 68.2% of the set standard deviations from the mean account for about 95.4% and three standard deviations from the mean account for about 99.7%. ```
 expressions/618315: foil method (5a+2) (a-5) 1 solutions Answer 388818 by ewatrrr(10682)   on 2012-06-06 07:08:01 (Show Source): You can put this solution on YOUR website! ``` Hi, foil method (5a+2) (a-5) = F First terms a^2 O Outside terms -25a I Inside terms 2a L Last terms -10 ```
 Triangles/618096: The segment is parallel to one side of the triangle. Find the values of x and y . (Angle) ---> https://media.glynlyon.com/a_matgeo_2011/5/a2.gif x = ? y = ?1 solutions Answer 388733 by ewatrrr(10682)   on 2012-06-05 16:58:01 (Show Source): You can put this solution on YOUR website! ``` Hi, segment parallel to one side of the triangle forms Similar Triangles: Corresponding sides of similar triangles are proportional. , Cross Multiplying to solve y = 8 , Cross Multiplying to solve 2x + 24 = 60 2x = 36 x = 18 ```
 Triangles/618104: A line through(2 , 1)meets the curve x squared - 2x - y=3 at A(-2 , 5) and at B.Find the coordinates of B.1 solutions Answer 388712 by ewatrrr(10682)   on 2012-06-05 15:56:44 (Show Source): You can put this solution on YOUR website! ``` Hi, A line through(2 , 1)meets the curve x^2- 2x - y=3 at A(-2 , 5) and at B the line passing through (2,1) and (-2,5) (2,1) and (-2,5) m = -4/4 = -1 y = -x + b 1 = -2 + b ||Using PT(2,1) to solve for b 3 = b = -x + 3 AND x^2- 2x - y=3 or = x^2- 2x - 3 x^2-2x-3 = -x + 3 x^2-x - 6 = 0 (x-3)(x+2) = 0 (x+2) = 0 We have A(-2 , 5) (x-3) = 0 B(3,0) ||| = -x + 3 ```
 Radicals/618114: 5+ROOT(a+7)=a or 5+√(a + 7)=a please show all your work, and here is what i did 5+√(a + 7)=a 5=√(a + 7)+a 25=a+7+2a 25=2a+a+7 2a+a-18 but thats wrong, where did i make a mistake and please work out this problem thank you1 solutions Answer 388705 by ewatrrr(10682)   on 2012-06-05 15:34:34 (Show Source): You can put this solution on YOUR website! ``` Hi, |||Need to isolate the radical on one side the EQ a^2- 11a + 18 = 0 factoring: (a-9)(a-2) = 0 (a-9)= 0 a = 9 (a-2) = 0 a = 2 ```
 Percentage-and-ratio-word-problems/617115: Find the range, standard deviation, and variance for the following sample data: 89, 6, 96, 43, 11, 30, 30, 77, 34, 67, 60, 5, 91, 26, 93, 22 1 solutions Answer 388158 by ewatrrr(10682)   on 2012-06-02 12:45:10 (Show Source): You can put this solution on YOUR website! ``` Hi, Previously Posted Find the range, standard deviation, and variance for the following sample data: 89, 6, 96, 43, 11, 30, 30, 77, 34, 67, 60, 5, 91, 26, 93, 22 Entering Date is Excel spreasheet column and Using the Data Analysis Tool... mean: 780/16 = 48.75 variance: 1080.467 standard deviation: = 32.87 ```
 Probability-and-statistics/617133: Assume that average annual salary for a worker in th u.s. is \$39,000 and the annual annual salary for americans are normally distributed with a standard deviation equal to \$7,000 find the following A) what percentage of americans earn below \$25,000 B) what percentage of americans earn above \$44,0001 solutions Answer 388155 by ewatrrr(10682)   on 2012-06-02 12:21:20 (Show Source): You can put this solution on YOUR website! ``` Hi, Assume that average annual salary for a worker in th u.s. is \$39,000 and the annual annual salary for americans are normally distributed with a SD = \$7,000 P(X<25) = P(z < -2) NORMSDIST (-2) = .0228, 2.28% P(X >44) = 1- P(z < (44,000 - 39,000)/7000) = 1 - P(z< .7143) = 1- .7325 = .2375, % ```
 Percentage-and-ratio-word-problems/617130: Household income does not tend to follow a normal distribution in a particular state, yet average income is approximately \$45,000/year in this state, with a standard deviation of about \$9000. Within what income range would approximately 89% of the household incomes lie within this state? Show all work as to how this is obtained.1 solutions Answer 388153 by ewatrrr(10682)   on 2012-06-02 12:08:11 (Show Source): You can put this solution on YOUR website! ``` Hi, average income is approximately \$45,000/year in this state, with a SD of about \$9000. using a normal distribution to approximate values that % of houseolds lie 1-.89 = .11, .11/2 = .055 Excel NORMSINV(.055)gives z = 1.59819 1.59819 = (X -45000)/9000 X = 1.598*9000 + 45000 = \$59,382 and -1.59819 = (x -45000)/9000 x = -1.598*9000 + 45000 = \$30,618 ```
 Trigonometry-basics/617118: Solve the following equations in the interval [0, 2pi]. 1) cos(t)= (1/2) t= 2) cos(t)= -(sqrt2/2) t=1 solutions Answer 388152 by ewatrrr(10682)   on 2012-06-02 11:49:04 (Show Source): You can put this solution on YOUR website! ``` Hi, Solve the following equations in the interval [0, 2pi]. 1) cos(t)= (1/2) t = 60° , 300° 2) t = 135° , 225° Thought You may find this Unit Circle (cosx,sinx) presentation helpful in Your studies ```
 Percentage-and-ratio-word-problems/617047: For a particular sample of 77 scores on a psychology exam, the following results were obtained. First quartile = 42 Third quartile = 69 Standard deviation = 10 Range = 54 Mean = 62 Median = 56 Mode = 83 Midrange = 66 Answer each of the following: I. What score was earned by more students than any other score? Why? II. What was the highest score earned on the exam? III. What was the lowest score earned on the exam? IV. According to Chebyshev's Theorem, how many students scored between 32 and 92? V. Assume that the distribution is normal. Based on the Empirical Rule, how many students scored between 52 and 72? Please show all of your work. 1 solutions Answer 388147 by ewatrrr(10682)   on 2012-06-02 11:16:52 (Show Source): You can put this solution on YOUR website! ``` Hi, For a particular sample of 77 scores on a psychology exam, the following results were obtained. First quartile = 42 Third quartile = 69 Mean = 62, Median = 56 I. What score was earned by more students than any other score? by defn. II. What was the highest score earned on the exam? , x = III. What was the lowest score earned on the exam? IV. According to Chebyshev's Theorem, how many students scored between 32 and 92? , = 76.23 or 76 V. Assume that the distribution is normal. Based on the Empirical Rul... how many students scored between 52 and 72? OR 52 The empirical rule says that if you go 1 standard deviation out from the mean that you will capture 68 % of your data Please show all of your work. ```
 Percentage-and-ratio-word-problems/617048: Find the range, standard deviation, and variance for the following sample data: 89, 6, 96, 43, 11, 30, 30, 77, 34, 67, 60, 5, 91, 26, 93, 22 1 solutions Answer 388143 by ewatrrr(10682)   on 2012-06-02 10:30:14 (Show Source): You can put this solution on YOUR website! ``` Hi, Find the range, standard deviation, and variance for the following sample data: 89, 6, 96, 43, 11, 30, 30, 77, 34, 67, 60, 5, 91, 26, 93, 22 Entering Date is Excel spreasheet column and Using the Data Analysis Tool... mean: 780/16 = 48.75 variance: 1080.467 standard deviation: = 32.87 ```
 Functions/617102: Solve then graph. t+20>=7 The solution is {t l t >= -13} -what is the solution to the graph on a number line?1 solutions Answer 388139 by ewatrrr(10682)   on 2012-06-02 10:20:12 (Show Source): You can put this solution on YOUR website! ``` Hi, Solve then graph. t+20 ≥ 7 Yes, t ≥ -13 to graph on a number line, one would use an arrow to the from t = -13, (the arrow including the dot on -13) ```
 Linear-equations/617101: 4 - 5 a = -20 The four and five thing is a fraction 1 solutions Answer 388138 by ewatrrr(10682)   on 2012-06-02 10:15:30 (Show Source): You can put this solution on YOUR website! ``` Hi, a = -25 ```
 Systems-of-equations/617107: Please help with this question. Keiko bicycles 8km/h faster than Javier. In the same time it takes Javier to bicycle 30 km, Keiko can bicycle 54 km. How fast does each bicyclist travel? Javier travels ___ km/h Keiko travels ___ km/h1 solutions Answer 388135 by ewatrrr(10682)   on 2012-06-02 10:12:37 (Show Source): You can put this solution on YOUR website! ``` Hi, Keiko bicycles 8km/h faster than Javier. Let x and (x+8) represent Javier's and Keiko's speeds respectively Question states*** Note: D = rt or D/r = t In the same time it takes Javier to bicycle 30 km, Keiko can bicycle 54 km. Cross Multiplying to solve 54x = 30x + 240 24x = 240 x = 240/24 =10kmph, Javier's speed. Keiko's speed is 18kmph ```
 Mixture_Word_Problems/617108: You received an order to prepare 500 ml of a 0.6% KCl solution. Your pharmacy only has a 10% KCl solution in stock. How many milliliters of the stock KCl solution would you need to prepare this solution? How much distilled water do you need to add to produce the final product1 solutions Answer 388132 by ewatrrr(10682)   on 2012-06-02 10:04:24 (Show Source): You can put this solution on YOUR website! ``` Hi, preparing 500 ml of a 0.6% KCl solution from 10% KCl solution & distilled water Water = Water x = 200ml of distilled water needs to be added ```
 Probability-and-statistics/617081: A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 180 was taken, and the mean amount spent was \$219.76. Assuming a standard deviation equal to \$41.77, find the 99% confidence interval for µ, the mean for all such families. 1 solutions Answer 388125 by ewatrrr(10682)   on 2012-06-02 09:23:55 (Show Source): You can put this solution on YOUR website! ``` Hi, A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 180 was taken, and the mean \$219.76. Assuming SD = \$41.77, find the 99% confidence interval for µ, the mean for all such families. ME = 2.576[41.77/sqrt(180)] ----- CI: 219.76-ME < u < 219.76 + ME ```
 Probability-and-statistics/617083: The following data lists the average monthly snowfall for January in 15 cities around the US: 40 44 43 15 22 29 38 22 14 13 28 29 47 31 18 Find the mean, variance, and standard deviation.1 solutions Answer 388123 by ewatrrr(10682)   on 2012-06-02 09:17:40 (Show Source): You can put this solution on YOUR website! ``` Hi, The following data lists the average monthly snowfall for January in 15 cities around the US: 40 44 43 15 22 29 38 22 14 13 28 29 47 31 18 Find the mean, variance, and standard deviation. Entering Date is Excel spreashett column and Using the Data Analysis Tool... mean: 433/15 = 28.8667 variance: 131.981 standard deviation: = 11.4883 ```
 Equations/617096: What is 6x + 5 = 13 + 2x1 solutions Answer 388121 by ewatrrr(10682)   on 2012-06-02 09:10:08 (Show Source): You can put this solution on YOUR website! ``` Hi, Note: use of non-caps, much easier to read for most. 6x + 5 = 13 + 2x 4x = 8 x = 2 ```
 Rational-functions/617085: Rational Expressions : {(y/(y^2 - 1)}-{y/(y^2-2y+1)}(y-1/y+1) problem in doing the L.C.M1 solutions Answer 388119 by ewatrrr(10682)   on 2012-06-02 09:08:11 (Show Source): You can put this solution on YOUR website! ``` Hi, If I am understanding the format Properly: - - - - = 0 ```
 Proportions/617089: The advertisement price of potatoes is 35 cents per pound. If a 3-pound bag actually weighs 3 1/4 pounds, what is the closest approximation in cents to the actual price per pound for that bag?1 solutions Answer 388116 by ewatrrr(10682)   on 2012-06-02 08:52:57 (Show Source): You can put this solution on YOUR website! ``` Hi, re TY... appears that 3.25lb bag was sold for 1.05 (price of 3lb bag) The advertisement price of potatoes is 35 cents per pound. If a 3-pound bag actually weighs 3 1/4 pounds,what is the closest approximation in cents to the actual price per pound for that bag Assuming the bag ( that actually weighs 3.25lb) is purchased for the price of a 3lb bag: = \$1.05 and = .32˘/lb ```
 Permutations/617092: 6 people are going to play a ball game. Each team has 3 players. How many different team combinations are possible?1 solutions Answer 388115 by ewatrrr(10682)   on 2012-06-02 08:46:02 (Show Source): You can put this solution on YOUR website! ``` Hi, 6 people are going to play a ball game. Each team has 3 players. How many different team combinations are possible? 6C3 = 6!/(3!3!) = 20 possible ```
 Probability-and-statistics/617087: A researcher claims that the average age of people who buy lottery tickets is 65. A sample of 30 is selected and their ages are recorded as shown below. The standard deviation is 6. At a = 0.05 is there enough evidence to reject the researcher’s claim? 49 63 90 52 22 80 72 56 82 56 24 46 70 74 70 61 65 71 39 74 79 76 71 49 62 68 71 67 69 45 1 solutions Answer 388114 by ewatrrr(10682)   on 2012-06-02 08:43:00 (Show Source): You can put this solution on YOUR website! ``` Hi, A researcher claims that the average age of people who buy lottery tickets is 65 Sample mean of the 30 ages is 62.4 and sample SD = 16 z = = -.89 Sample size 30, Degree of Freedom 29, a = 0.05%, (z = -2.05) NOT enough evidence to reject researcher's claim ```
 Linear-systems/616306: x+y=7 and 2x-y=2 then y=? 2x+y=4 and 3x-2y=13 then x=? 1 solutions Answer 388111 by ewatrrr(10682)   on 2012-06-02 07:52:31 (Show Source): You can put this solution on YOUR website! ``` Hi Solution to the following system: x+y=7 2x-y=2 3x = 9, x = 3 and y = 4 2x+y=4 and ||||multiplying 1st EQ thru by 2 to eliminate the y variable 3x-2y=13 4x+2y=8 and ||||Result of multiplying 1st EQ thru by 2 to eliminate the y variable 3x-2y=13 7x = 21, x = 3 and y = -2 (2x+y = 4 or y = 4-2x) ```