1. prealgebra/ check answer please

    John who is an amateur golfer spends 3 hours every day practicing golf. What percentage of his waking hours does John spend practicing golf if he sleeps 9 hours a day? 24-9=15 3/15= 0.2 0.2 x 100 = 20% spent practicing
  2. Math

    The following table represents a grouped frequency distribution of the number of hours spent on the computer per week for students. What percentage of students used the computer between 7 and 14.9 hours per week? Round your answer to one decimal place, if
  3. Math

    A random survey of 500 households determines that 20% of the households would do so and that each participating household expects to recycle about 100 cans monthly with a standard deviation of 30 cans. Question (a) What is the 95% confidence interval
  4. AP Stats

    Bolivian adult females are much shorter than US females although the standard deviation of their heights is about the same at 2.3 inches. Only 4.1% of Bolivian females are at least five feet tall. What is the mean height of adult Bolivian women assuming
  5. Chemistry

    A 3.23 gram sample of a sodium bicarbonate mixture was reacted with excess acid. 48.52 mL of the evolved gas was collected over water at 0.930 arm and 23.0 degrees Celsius. What is the percentage of sodium bicarbonate in the original mixture? The pressure
  6. maths

    There are 40 students in a class.14 of these students are girls. What percentage of the class are girls?
  7. chemistry

    A fully sealed 50m^3 room at atmospheric pressure and temperature 20C contains two ballons, one containing helium and the other containing oxygen. The balloons each have a volume of 0.5m^3 and have gauge pressure 2m of water. The balloons are ruptured and
  8. Science

    Choose the explanation that does the following: (1) identifies the element used in carbon dating and (2) explains why the element is used. A. iodine-131; iodine is present in the thyroid glands, is radioactive, and has a very long half-life B. nitrogen-14;
  9. Math

    A pendulum of Length L cm has time period T seconds. T is directly proportional to the square root of L. The length of the pendulum is increased by 40%. What is the percentage increase in the time period? ???????? Multiplier for increasing L = 1.4
  10. math, 7th

    If there are 100 marbles, 10 red, 20 white, 30 blue, and 40 green, and you were to choose only one out of a bag, what is the probability that it wouldn't be red, white, or blue? The probability would be 40 out of 100 -- or 4 out of 10. What percentage is
  11. buisness statics

    Mean yearly salary of employes of a company wasRs20,000.mean yearly sakaries of male and female employes were Rs 20,800 and 16,800.find out the percentage of male and female employed by the company??b
  12. College Math

    Ted stops by a club every Friday night and spends $50. He also spends $350 each month on groceries. Ted's spending at the club is what percentage of his groceries expenses. Assume that 4 Friday's per month.
  13. math

    The figure below is not drawn to scale. The ratio of the area of triangle ABC to the area of triangle DEC to the area of triangle FGH is 7 : 5 :3. If 20% of the area of triangle DEC is shaded, what percentage of the figure is unshaded? PLEASE SHOW ALL YOUR
  14. accounting

    Uncollectible Accounts—Percentage of Sales Ryan's Express has total credit sales for the year of $178,000 and estimates that 3% of its credit sales will be uncollectible. Record the end-of-period adjusting entry on December 31, in general journal form,
  15. accounting

    Uncollectible Accounts—Percentage of Sales Ryan's Express has total credit sales for the year of $178,000 and estimates that 3% of its credit sales will be uncollectible. Record the end-of-period adjusting entry on December 31, in general journal form,
  16. chemistry

    A common way of producing hydrogen gas in the lab is by reacting zinc with hydrochloric acid. Zn (s) + 2 HCl (aq) -> ZnCl2 (aq) + H2 (g) A sample of impure zinc, of mass 5.10g, reacted with an excess of hydrochloric acid solution 3.0 mol dm-3
  17. Biology

    In order to predict the percentage of males and females three assumptions must be considered: 1. The X carrying sperm and Y carrying sperm have an equal chance of fetilization: 2. The egg and sperm combine at random: 3. the XX and XY zygotes have equal
  18. Physics

    Gold-198 with a half life of 2.6 days is used to diagnose and treat liver disease. Write a half life decay equation that relates the mass of au-198 remaining to time in days. What percentage of a sample of Au-198 would reamin after 1 day, 1 week? Given the
  19. Maths GRE

    A salesman receives a commission of c% on a sale of D dollars. Find his commission. A)cD B)cD/100 C)100cD D)c/100D E)100c/D Any number expressed as a percentage is that number divided by 100 expressed as a decimal. Thus c% is c/100 Multiplying that by the
  20. Chemistry

    Ascorbic acid (vitamin C) is a diprotic acid having the formula H2C6H6O6. A sample of a vitamin supplement was analyzed by titrating a 0.3252 g sample dissolved in water with 0.0284 M NaOH. A volume of 13.27 mL of the base was required to completely
  21. Finance

    The Evanec Company’s next expected dividend, D_1, is $3.18; its growth rate is 6%; and its common stock now sells for $36.00. New stock (external equity) can be sold to net $32.40 per share. What is Evanec’s cost of retained earnings, r_s? What is
  22. Chemistry

    Ascorbic acid (vitamin C) is a diprotic acid having the formula H2C6H6O6. A sample of a vitamin supplement was analyzed by titrating a 0.3252 g sample dissolved in water with 0.0284 M NaOH. A volume of 13.27 mL of the base was required to completely
  23. Finance

    The Evanec Company’s next expected dividend, D_1, is $3.18; its growth rate is 6%; and its common stock now sells for $36.00. New stock (external equity) can be sold to net $32.40 per share. What is Evanec’s cost of retained earnings, r_s? What is
  24. Chemistry

    If performing a gravimetric sulfate experiment and you use ordinary filter paper instead of ashless filter paper, would results be too high or too low? If I'm trying to calculate percentage of sulfate in a sample and I used ordinary filter paper, the paper
  25. macroeconomics

    Please note that we don't do students' homework for them. Once YOU have come up with a response to YOUR questions, please re-post and let us know what you think. Then someone here will be happy to critique your work. =) Use the circular flow diagram to
  26. math

    Karl has an annual salary of $22,000 and pays $250 each month for car insurance. a) Find Karl’s annual cost for car insurance b) Karl’s payments on car insurance is what percentage of his annual income?State your answer to the nearest whole number.
  27. math

    Nick has a revolving department store credit card account with an annual percentage rate of 15%.Last month's balance on the account was 423.78.During the current month,he made purchases totaling 123.42 and made a payment of 100.00.The store uses the unpaid
  28. Statistics

    The average grade point average(GPA)of undergraduate students in New York is normally distributed with a population mean of and a population standard deviation of. Compute the following, 1)The percentage of students with GPA'S between 2.0 and 2.6 2)If a
  29. Calculus

    y = 1/2x^2-x + 3 for 0_<x_<6. (b) Calculate the mid-ordinates of 5 strips between x = 1 and x = 6, and hence use the mid- ordinate rule to approximate the area under between x = 1, x = 6 and the x-axis. (c) Assuming that the area determined by
  30. URGENT! chemistry- percentage yield

    heating an ore of antimony sulfide in the presence of iron gives th element antimony and iron(2) sulfide. when 15.0 antimony sulfide reacts with an excess of iron, 9.84 g antimony is produced. what is the percent yield of this reaction?
  31. Math

    We believe that 77​% of the population of all Business Statistics I students consider statistics to be an exciting subject. Suppose we randomly and independently selected 38 students from the population. If the true percentage is really 77​%, find the
  32. Chemistry

    An aqueous solution of ethyl alcohol is made by transfering 1.32 mL of liquid ethyl alcohol to a 50.0 mL volumetric flask, and then adding enough water to fill the flask to the mark. What is the volume/volume percentage of ethyl alcohol in the solution?
  33. MATH

    Suppose a third world country in the last five years is now expanding their Internet access. If they went from 2.5% of their citizens having access to the Internet to 7.5% now having access, calculate the following: a) How many percentage points did they
  34. math

    Suppose a third world country in the last five years is now expanding their Internet access. If they went from 2.5% of their citizens having access to the Internet to 7.5% now having access, calculate the following: a) How many percentage points did they
  35. adult education

    You are a share analyst for an investment firm and are investigating the return on shares in the Mean Corporation over the last four years. The return on Mean Corporation shares over the last four years is presented. Calculate the geometric mean rate of
  36. Science

    Which fact provides the best evidence for the scientific theory of the evolutionary development of life on the earth? a. fossils are found almost exclusively in sedimentary rocks b. characterisitcs of simpler forms of life can be found in more complex
  37. Dr. Bob

    Okay now can you read my introduction for me please... INTRODUCTION: This report discusses an experiment to study the percent mass of iron determined by the concentration of a colored iron solution from the absorbance of the spectrometer. This lab is
  38. physics

    Can someone tell me if my answers are correct? A .145 kg block of wood hangs from the ceiling by a string. A bullet with a mass of .004 kg and a speed of 540 m/s strikes the block. After the collision, the block with the bullet embedded rises 42 cm up. a)
  39. Financial Management

    National Telephone and Telegraph Company common stock currently sells for $60 per share. NTT is expected to pay a $4 dividend during the coming year, and the price of the stock is expected to increase to $65 a year from now. Determine the expected
  40. chemistry

    A 0.50 g mixture of Cu and CuO was treated with hydrogen at elevated temperature. CuO was reduced to Cu . (b) Before the experiment, calculate the minimum amount (in mole) of hydrogen required to ensure the reduction is completed. (3 marks) (c) After
  41. physics

    A refrigerator with a weight of 1,127 newtons needs to be moved into a house using a ramp. The length of the ramp is 2.1 meters, and its height is 0.85 meters. What is the percentage efficiency if a force of 496 newtons is applied to the refrigerator? 44
  42. Stats

    1. The question asks to choose a data point in our graph (we chose 476,44) of median home prices (x) and percentage of students who scored Advanced on math MCAS (y). We have to find the residual. I'm confused because the equation I was given is e=y-yhat I
  43. Stats

    1. The question asks to choose a data point in our graph (we chose 476,44) of median home prices (x) and percentage of students who scored Advanced on math MCAS (y). We have to find the residual. I'm confused because the equation I was given is e=y-yhat I
  44. adult education

    An oblique collision occurs between two objects with a similar rectangular shape (1m x 0.2m) as shown below. The first object has a mass of 10 kg and is initially traveling at 4 m/s. The second object has a mass of 6 kg and is initially at rest. The impact
  45. chemistry

    a sample iron ore is dissolved in an acidic solution in which yhe iron is converted into fe2+. the solution formed the titrated with kmno4 which oxidies fe2+ to fe3+ while kmno- ions are reduced to mn2+. 92.95 ml of 0..02M of kmno4 is required for
  46. Math

    Ken planted 8 flowers and 4 shrubs in his mother's garden. He ran out of fertilizer before he planted 2 of the flowers and 1 of the shrubs, so he planted them without fertilizer. What percentage of plants were planted without fertilizer? A. 12.5% B.25% C.
  47. math

    Water is being poured into a conical cup that is 12cm tall. a) When the water in the cup is 9cm deep, what percentage of the cup is filled? b) When the cup is 75 percent filled, how deep is the water?
  48. Algebra HELP!

    The student bookstore had a textbook for sale at $89.95. A student found the textbook on eBay for $62.00. If the student bought the book on eBay, what percentage of the cost of the bookstore book did she save?
  49. science

    The atmosphere is composed of a mixture of _______________, _____________ ____________, and tiny___________________. Thank you for using the Jiskha Homework Help Forum. The origin of our atmosphere is still open to a great deal of speculation. One theory
  50. STATISTICS

    In a survey of 1000 registered U.S. voters, 55% respond that they support health care reform. What is the 95% confidence interval for the true percentage of U.S. registered voters who support health care reform? 50%-60% 55%-60% 51%-59% 52%-58% 49%-47%
  51. statistics

    In determining monthly seasonal indexes for gas consumption, the sum of the 12 means for gas consumption as a percentage of the moving average is 1150. To get the seasonal indexes, each of the 12 monthly means is to be multiplied by?
  52. Chem

    A mixture of 5.00 g of sodium carbonate, Na2CO3 and sodium hydrogen carbonate, NaHCO3 is heated. The loss in mass is 0.31 g. Sodium carbonate does not decompose on heating. Calculate the percentage by mass of sodium carbonate in the mixture.
  53. Chemistry

    A student places 0.025 moles of solid sulfur and 0.100 moles of nitrogen monoxide gas in a closed 1.00L container and 0°c for several days. Calculate the number of molecules of NO in the 1.00L container after equilibrium is reached, given the following
  54. Math

    Seven students took a quiz. Four of these students received a score above 85 percent. Students who received at least an 85 percent go a sticker. What percent of the students ( rounded to the nearest full percentage number) received a sticker? I came up
  55. general chemistry

    I need the oxidation half reactions, reduction half reactions, and net ionic equations for the following reactions: 1)magnesium +0.1M zinc sulfate 2)copper+0.1M zinc sulfate 3)zinc+0.1M copper(II)sulfate 4)zinc+3M HCl 5)copper+3M HCl 6)0.1M potassium
  56. Math!

    Wasim is paid on a graduated scale of 5% on the first $10,000 of sales in a month, 7% on the next $25,000, and 9% on all additional sales. a)What will he be paid in a month in which sales are $62,760? (round the answer to the nearest cent.) b)What fixed
  57. math who me step by step

    25g of a sample of ferrous sulphate was dissolved in water containing dilute h2s04 and the volume made up to one litre. 25ml of this solution required 20ml of N/10 kmn04 solution for complete oxidation. Calculate the percentage of fes047h20 in the sample
  58. math

    nick has a revolving department store credit card account with an annual percentage rate of 15% last month's balance on the account was $423.78 during the current month he made purchases totaling $123.42 and he made a payment of $100.00 the store uses the
  59. math

    The ratio of boys and girls in a class is 5:3 if 20 % of the boys and 60 % of girls have passed in first class what percentage of the class is in first class?
  60. Maths

    I got 30% on a 10-problem test, 70% on a 20-problem test and 80% on a 30-problem test. If the three tests are combined in one 60-problem test what percentage is my overall score?
  61. Math

    A grapefruit is 8% heavier than an orange, and an apple is 10% lighter than the orange. By what percentage is the apple lighter than the grapefruit?
  62. Math

    A grapefruit is 8% heavier than an orange, and an apple is 10% lighter than the orange. By what percentage is the grapefruit heavier than the apple?
  63. Probability and Statistics

    Hi, I am having a lot of trouble with Normal Distribution. I do online school and this lesson didn't really explain how to exactly complete the following problems. My teacher said that the answers to the problems below were all incorrect. I would greatly
  64. Texas State History

    1. Which statement best defines demography 2. What is meant by “natural population growth”? 3. By how much is the Hispanic population in Texas’ public schools expected to increase by 2040? 4. About what percentage of the population increase in Texas
  65. technology

    What is one of the strengths of line graphs? a) Line graphs show percentage in a whole b) Line graphs show change over time c) Line graphs compare values of individual groups or categories. d) Line graphs always show averages My answer is C
  66. Math

    Land growing continuous grain corn as a cash crop loses soil at a rate of 14.0 metric tonnes ha-1 yr-1. This is a fertile soil, which has an organic matter content of 3.8% and nitrogen content of 0.35% (both by mass). a)Calculate how long it will take to
  67. PHYSICS

    Two balls collide on a horizontal, frictionless table. Ball A has a mass of 0.175 kg and travelling at 1.20 m/s [E 40o S]. Ball B has a mass of 0.225 kg and is travelling at 0.68 m/s [E]. The velocity of ball B after collision is 0.93 m/s [E 23o S].
  68. Math - I really need help, please.

    A town has a population of 8400 i 1990. Fifteen years later, it's population grew to 12500. Determine the average annual growth rate of this town's population. I really don't understand this problem. I've been going at it for hours and all I've come to is
  69. Lincoln College Of New En

    The percentage of physicians who are women is 27.9% in a survey of physicians employed by a large university health system, 45 of 120 randomly selected physicians were women. Is there sufficient evidence at the 0.05 level of significance to conclude that
  70. Macroeconomics

    The Philips Curve Suppose the economy has been experiencing zero inflation and five percent unemployment for several years. The government decides to lower the unemployment percentage by generating some inflation. You need to do the following: 1.Using the
  71. Chemistry

    The following questions refer to the following acids and bases. A) Hydrazoic acid HN3 Ka = 1.9 x 10^-5 B) Hydrofluoric acid HF Ka = 6.8 x 10 ^-4 C) Nitrous Acid HNO2 Ka = 4.5 x 10^-4 D) Phenol C6H5OH Ka = 1.3 x 10^-10 E) Aniline C6H5NH2 Ka = 4.3 x 10^-10
  72. Statistic

    Heights of men on a baseball team have a​ bell-shaped distribution with a mean of 169 cm169 cm and a standard deviation of 9 cm9 cm. Using the empirical​ rule, what is the approximate percentage of the men between the following​ values? a. ​% of
  73. engr. econ.

    homeowener is considering refinancing his home. original amount of the 30 yr loan was 250,000 at 12% compounded monthly. The owner has made ten years of payments. how much is the remaining balance on the loan. this is what I gotL r=12%, m=12,
  74. biology

    1. A population which meets the hardy- weinberg requirements: a. Evolves b. is small and usually isolated c. has allele frequency in equilibrium d. changes genotypic distribution from generation to generation e. always has 75% A and 25% a allele
  75. ctu

    Stuart’s car loan reached a maturity value of $14001.00 after 3 years. Find the rate on Stuart’s loan if the principal he borrowed was $12474.00 Use the formula to find the interest; then use to find the rate in decimal form. Leave your answer in
  76. Chemistry - acid base

    A 50.0 mL sample of 1.50×10−2 M Na2SO4(aq) is added to 50.0 mL of 1.23×10−2 M Ca(NO3)2(aq). What percentage of the Ca2+ remains unprecipitated? What I did n=CV Na2SO4 = (1.50×10−2 M)(0.05L) = 0.00075 Ca(NO3)2 = (1.23×10−2 M)(0.05L) = 0.000615
  77. science

    A coach tells his little league players that hitting a 0.275 batting average, within 7% percentage error, means that they had a really great season. Seven year old Tommy ended the season hitting a 0.258 batting average. According to his coach, did he have
  78. math

    Each week, Bart earns a base rate of $85 and a commission on each dollar of merchandise he sells. If Bart sells $3600 in one week and c represents the commission percentage, which algebraic expression represents his earnings for that week? would the answer
  79. Statistics / Business

    According to the National Humane Society, "Stray Cost" or the cost of the care and feeding for a stray dog is $419.00 per year. This amount does not include veterinarian care, but only food, water and shelter. It was found that the standard deviation of
  80. Math

    Let's propose a hypothetical situation where you plan to apply your newly acquired analytical skills to the end of the baseball season. The Dodgers most recent win percentage is 0.569. Assume that the team that they are playing and home field advantage is
  81. math

    IF 81 PEOPLE NEED TO TAKE A TEST, BUT ONLY 13 HAVE ACTUALLY TAKEN TEST, WHAT IS THE PERCENTAGE OF PEOPLE WHO HAVE TAKEN TEST?
  82. chemistry

    Some distilled water is added to an empty beaker. A gram of copper(II) nitrate is added to the beaker with stirring. After a few minutes, what is in the beaker? a. solid copper(II) nitrate and water b. nitrogen gas, copper atoms, electrons, and water c. a
  83. Business math

    A watch with a list price of $889.00 is sold by a wholesaler at a net cost of $545.75. Find the single trade discount rate being offered. round to the nearest tenth of a percent 889.00*61.4? since trade discount equals list price * trade discount
  84. Chemistry

    a)How much would the freezing point change in a 2.5m solution of phenol in benzene? (freezing point of phenol is 7.40 degrees C, freezing point of benzene is 5.12 degrees C) b)How much would the boiling point change in a 1.0m solution of magnesium chloride
  85. chemistry help!

    Potassium has an atomic mass of 39.10amu. a sample of potassium is made up of isotopes potassium-39 (mass=38.964) and potassium-41(mass =40.962 amu). What percentage of the potassium sample is potassium-39? what percent of the sample is potassium-41?
  86. Physics

    A 14000 N automobile travels at a speed of 50 km/h northward along a street, and a 7500 N sports car travels at a speed of 62 km/h eastward along an intersecting street. (a) If neither driver brakes and the cars collide at the intersection and lock
  87. Public High School AP Biology

    I got a question that comes from the 1990 released test #61 that I'm completley lost on 61. In a population that is in Hardy-Weinberg equilibrium, the frequency of a recessive allele for a certain hereditary trait is 0.20. What percentage of the
  88. Physics

    A 14000 N automobile travels at a speed of 50 km/h northward along a street, and a 7500 N sports car travels at a speed of 62 km/h eastward along an intersecting street. (a) If neither driver brakes and the cars collide at the intersection and lock
  89. Public High School AP Biology

    I got a question that comes from the 1990 released test #61 that I'm completley lost on 61. In a population that is in Hardy-Weinberg equilibrium, the frequency of a recessive allele for a certain hereditary trait is 0.20. What percentage of the
  90. Algebra

    Alma can grade a batch of placement exams in 3hr and Kevin can grade a batch in 4hr. if they work together to grade a batch of exams, what percentage of the exams will have been graded by Alma?
  91. electrical

    A 35 kVA transformer supplies a load of 12 kW at a power factor of 0.45 lagging. Find the percentage of full load the transformer is carrying. If additional unity power factor loads are to be served with the same transformer, how many kW may be added
  92. prealgebra/ check answer please

    John who is an amateur golfer spends 3 hours every day practicing golf. What percentage of his waking hours does John spend practicing golf if he sleeps 9 hours a day? 24-9=15 3/15= 0.2% Answer I am unsure if the steps are right
  93. statistics

    In 2000, National data suggested that 26% of all U.S. businesses were owned by women. In 2009, a consulting firm surveyed a random sample of 700 U.S. businesses and found that 28% of them were owned by women. Is this evidence of an increase in the
  94. Math

    Last one! Please help! South America's total population was 515,000,000 and the world's total population was 6,279,000,000. What percentage was South America rounded to the nearest tenth?
  95. Chemistry

    Barium sulfate, BaSO4 is made by the following reaction. Ba(NO3)2(aq) + Na2SO4(aq)----> BaSO4(s) + 2NaNO3(aq) An experiment was begun with 91.77 g of Ba(NO3)2 and an excess of Na2SO4. After collecting and drying the product, 62.3 g of BaSO4 was
  96. chemistry

    A mixture of 3.00 g of silver and copper metals was dissolved in excess nitric acid. Resulting salts, silver(I) nitrate and copper(II) nitrate, were isolated and dissolved in enough water to make 0.100 L of a solution with a total concentration of the
  97. stat

    A company’s CEO wanted to estimate the percentage of defective product per shipment. In a sample containing 500 products, he found 30 defective products. (a) Find a 98% confidence interval for the true proportion of defective product. Show your
  98. math

    A company begins a radio advertising campaign in Chicago to market a new soft drink. The percentage of the target market that buys a soft drink is estimated by the function f(t)=100(1-e^-0.01t), where t is the number of days of the campaign. After how long
  99. math

    Let f(t) = Q0at = Q0(1 + r)t. f(7) = 75.94 and f(9) = 91.89 (a) Find the base, a. (Round your answer to two decimal place.) a = (b) Find the percentage growth rate, r. (Round your answer to the nearest percent.) r = % I honestly have no idea how to
  100. Math

    The Mills Lunch Shop prepares fresh take-out entrees each day. On Tuesday, 40 baked chicken dinners were prepared at a cost of $3.20 each. A 20% spoilage rate is anticipated. Mills Lunch Shop sells the dinners at an 80% markup based on cost. They decided