Most popular questions and responses by Devon
  1. Statistics

    Standard Normanl Drill: A. Find the number z such that the proportion of observations that are less than z in a standard Normal distribution is 0.8. B. Find the number z such that 35% of all observations from a standard Normal distribution are greater than

    asked on September 10, 2007
  2. Chemistry

    What is the mole fraction of ethanol, C2H5OH, in an aqueous solution that is 50.0% ethanol by mass?

    asked on August 22, 2016
  3. chemistry

    a solution of 2.5 M weak acid is .52% ionized. what is the Ka value of this acid? ive been stuck on this one for a long time and cant figure out where to even start...if someone could walk me through this itd be great! thanks

    asked on February 26, 2014
  4. physics

    A 905 kg test car travels around a circular track with a circumference of 3.25 km. If the magnitude of the force that maintains the car's circular motion is 2140 N, what is the car's tangential speed?

    asked on November 18, 2010
  5. pre-calc

    A ship travels 200km west from port and then 240km due south before it is disabled. Illustrate this in a vector diagram. Usa trigonometry to find the course that a rescue ship must take from port in order to reach the disabled ship. i don't know where to

    asked on March 30, 2008
  6. Math

    A projectile is fired with an initial velocity of 350 feet per second at an angle of 45° with the horizontal. To the nearest foot, find the maximum altitude of the projectile. The parametric equations for the path of the projectile are x = (350 cos

    asked on April 12, 2008
  7. social studies

    what significant effect did the treaty of paris signed after the french and indian war have on france. A. france had to withdraw to it's empire in central and south america B. france had to allow the british to claim settle the ohio vally C. france lost

    asked on October 14, 2018
  8. algebra

    The Kwon family has a rainwater catchment system they use to water their garden. After 3 days without rain, the depth of water in the tanks is 63 inches. After 5 days, the depth is 57 inches. Write an equation in point-slope form describing the situation

    asked on March 4, 2015
  9. chemistry

    Assume that no heat is lost to the surroundings and calculate the enthalpy involved when 200. mL of .10 M potassium hydroxide and 200. mL of .10 M hydrochloric acid are mixed. Both solutions began at room temperature, 24.5 degrees celsius, and have

    asked on April 14, 2014
  10. Calculus

    A 0.9 ml dose of a drug is injected into a patient steadily for half a second. At the end of this time, the quantity, Q, of the drug in the body starts to decay exponentially at a continuous rate of 0.4% per second. Using formulas, express Q as a

    asked on June 18, 2015
  11. math

    A class of 43 students took an exam. Their mean grade average is 67 and standard deviation is 7. a) how many students should get a C? b) how many should get a B? c) what score is necessary to get an A?

    asked on November 14, 2008
  12. math

    Jordana baked 4 apple pies. she wants to share them equally among 3 neighbors. what fractional part of the pies will each neighbor get?

    asked on March 15, 2019
  13. physics

    A freight train has a mass of 5 x 107 kg. If the locomotive can exert a constant pull of 12 x 105 N, how long would it take to increase the speed of the train from rest to 85 km/h

    asked on November 1, 2010
  14. Physics

    A cylindrical diving bell 4.0m tall, with an open bottom, is lowered to the bottom of a lake on a day when atmospheric pressure is 100 kPa. It is observed that water rises inside the bell to within 1.0m of the top. A)What is the pressure of the air trapped

    asked on May 4, 2011
  15. math

    i don't really know how to go about anwsering this problem: the weight of the eggs produced by a certain breed of hen is Normally distributed with mean 65 grams and standard deviation 5 grams. think of cartons of such eggs as SRSs of size 12 from the

    asked on October 8, 2007
  16. math

    A study to determine whether or not a football filled with helium traveled farther when kicked than one filled with air found that while the football filled with helium went, on average, farther than the one filled with air, the difference was not

    asked on October 7, 2007
  17. physics

    A girls sits on a tire that is attached to an overhanging tree limb by a rope. The girl's father pushes her so that her centripetal acceleartion is 3.8 m/s2. If the length of the rope is 3.3 m, a) what is the girl's tangential speed? b) If the magnitude of

    asked on November 18, 2010
  18. Chemical Compounds

    How can a flow chart help you to name chemical compounds? Some people like to memorize rules and use the analysis of compounds then to apply the rules. CAN YOU HELP ME!!

    asked on January 9, 2007
  19. physics

    Approximate the gravitational force of attraction between a 42.0 kg girl and a 56.0 kg boy if they are sitting 3.0 m apart in physics class.

    asked on December 2, 2010
  20. science

    I need an example of an acrostic poem for the word kinetic please help!!!!!!

    asked on May 13, 2013
  21. trig

    it says to verify the following identity, working only on one side: cotx+tanx=cscx*secx Work the left side. cot x + tan x = cos x/sin x + sin x/cos x = (cos^2 x +sin^2x)/(sin x cos x) = 1/(sin x cos x) = 1/sin x * 1/cos x You're almost there. thanks so

    asked on May 7, 2007
  22. Math

    A wheel with radius 2 cm is being pushed up a ramp at a rate of 6 cm per second. The ramp is 520 cm long, and 260 cm tall at the end. A point P is marked on the circle. How far does the wheel travel in one rotation?

    asked on May 4, 2014
  23. physics

    A 25 kg chair initially at rest on a horizontal floor requires 360 N horizontal force to set it in motion. Once the chair is in motion, a 316 N horizontal force keeps it moving at a constant velocity. a) Find the coefficient of static friction between the

    asked on November 8, 2010
  24. Chemistry

    Hydrogen boils at 20K. What is the boiling point of hydrogen on the Celsius scale? K is 273.15 degrees plus the celsius. so take 20(K) and minus 273.15 this would give your answer in celsius thanks.. One more question What is the volume of a board that

    asked on January 18, 2007
  25. statistics

    about what percent of the bags of pet food weigh less than 49.8 lb?

    asked on March 3, 2013
  26. Math

    A bottle of water costs $1.50. Explain how you would make a graph of four ordered pairs to model the total cost of the water in terms of the number of bottles.

    asked on March 16, 2015
  27. Physics

    A computer hard drive rotates at 5400 revolutions per minute. Starting from rest, what torque will get the hard drive up to that speed in just 150 revolutions? The moment of inertia of the hard drive is 1.3×10^-2 kg·m^2. I know the answer is 2.2 N.m, but

    asked on December 5, 2014
  28. Math

    The sticker price of car is $15,800. If the sales tax is 8% what is the total cost? Show working

    asked on January 31, 2012
  29. Chemistry HELP PLEASE!!

    write the oxidation and reduction half-reactions that occur at the anode and cathode, respectively, when MgCl2 liquid is electrolyzed using inert electrodes. HELP PLEASE!!!

    asked on March 20, 2014
  30. Physics

    (the drawing is of a square with each side equaling L and the opposites of each corner are equal to each other, so the mystery corner would be 3I) Four parallel long straight wires are carrying current perpendicular to the page, and the points at which

    asked on March 6, 2012
  31. Math

    At a summer camp there are 60 girls and 30 boys. Twenty percent of girls and 40% of boys passed the swimming test. What percent of the campers passed. Please show working.

    asked on February 12, 2012
  32. Ms. Sue

    Say you make the following assumptions: 1. Afarmer lives on 1 hen per day for a year. (2.)1 hen eats 25 grasshoppers per day (3.)1,000 grasshoppers have a mass of 1 kg (4.) 1 grasshopper requires about 30g of soy beans per year (5.) 1 human requires about

    asked on July 14, 2009
  33. Economics

    A person must decide whether or not to proceed with a particular investment project. If the project succeeds, She will gain $15 million. If the project fails, she will lose $3 million. She estimates there is a 20% chance that the project will succeed and

    asked on February 25, 2008
  34. (Life)

    What is a good conflict resolution technique for employees? Talk together. Work it out. Compromise. If you cannot do this, consult your employer. Are you talking about conflict resolution among employees or between employees and employers? Elizabeth's

    asked on March 23, 2007
  35. physics

    An apple (0.100 kg) is thrown vertically upward at a speed of [let x = any whole number between 10 and 20] m/s (from an arm 1.5 m off of the ground). What is the maximum height that the apple reaches? (g=9.8 m/s2)

    asked on November 11, 2015
  36. chemistry

    in regards to electrochemistry, Can Na metal displace Zn2+ in a single replacement reaction?

    asked on March 6, 2014
  37. Physics

    A fossil-fuel power plant that generates 1000MW of electrical power discharges 1600MJ per second as waste heat into the river. A)At what rate(in MW) is thermal energy obtained fromt the burning of coal? B)What is the thermal efficiency(power output/heat

    asked on May 4, 2011
  38. physics

    A tugboat pulls a ship with a constant net horizontal force of 5200 N and causes the ship to move through a harbor. How much work is done on the ship if it moves a distance of 3 km?

    asked on December 9, 2010
  39. Mathematics

    In the universal set (U) reperesents all the students in a class.The set m represents the student who take (Music 3x).The set D represents the students who take (Drama 7+x).If 24 students take Music, calculate The number of students who take BOTH music and

    asked on June 19, 2009
  40. physical science

    can volcanoes form anywhere on earth why or why not

    asked on May 12, 2009
  41. Math

    convert the number to scientific notation. .0000000009

    asked on December 16, 2008
  42. math

    A fitness company surveyed the weights of its 90 costumers. Assume that the weights are normally distrubted with a mean of 162 lbs and a standard deviation of 3.5 lbs. If you select one of its costumers randomly, what is the probability that the costumer's

    asked on November 14, 2008
  43. Physical science

    In my tenth-grade-level physical science class, we're studying heat, and I completely don't get it. I'll read the definition for specific heat over and over, and I still don't understand it. "For all substances, specific heat is a characteristic physical

    asked on October 18, 2007
  44. trig

    it says solve for all real solutions, compute inverse functions to 4 sigfigs. cos^2x=3-5cosx Devon, what grade level are these questions from? I am having the same problems as with your 9:14 post. Please see my partial solution in the post to bobpursely at

    asked on April 16, 2007
  45. Chemistry

    How do i balance this equation? Al+N2---->AlN 2Al + N2 ----> 2AlN

    asked on March 20, 2007
  46. physicss

    What average force is required to stop an 1100 kg car in 9.1 s if it is traveling at 83 km/h?

    asked on November 1, 2010
  47. Math

    The park department planted oak and mapel trees in a 5 to7 ratio. They planted 360 trees. How many mapel did they plant?

    asked on September 12, 2017
  48. Math

    1. Gerald received the following test scores in math class: 76, 86, 89, 81, and 99. What was Gerald’s average test score, rounded to the nearest point?

    asked on September 19, 2016
  49. algebra

    use the quadratic formula to find the roots of the equation. round to the tenths place,if necessary 11x^2-x-3=0

    asked on April 24, 2014
  50. math

    solve 27^2x-1=(1/81)^x

    asked on May 17, 2012
  51. Math

    A bill for a meal is $10.38 including tax. Find the total cost if the customer leaves a 15% tip.

    asked on February 12, 2012
  52. Math

    A test has 125 items. Each correct answer earns 1point and 65% is a passing grade. If you get 42 answers wrong will you pass? Show working

    asked on February 12, 2012
  53. Physics

    A fish at a pressure of 1.1 atm has its swim bladder inflated to an initial volume of 8.16 mL. If the fish starts swimming horizontally, its temperature increases from 20.0 degrees Celsius to 22.0 degress Celcius as a result of exertion. A)Since the fish

    asked on May 4, 2011
  54. physics

    A 7 kg bucket of water is raised from a well by a rope. If the upward acceleration of the bucket is 1.4 m/s2, find the force exerted by the rope on the bucket of water.

    asked on November 1, 2010
  55. physics

    A small weather rocket weighs 15.5 N. The rocket is carried up by the balloon. The rocket is released from the balloon and fired, but its engine exerts an upward force of 11.0 N. What is the acceleration of the rocket?

    asked on October 3, 2010
  56. Algebra

    x^3-2x^2-9x-2 is greater than or equal to -20. I got (-9+x^2)(x-2)(x-2). That would mean for the first grouping, the answer would be -3 or 3. My book listed them separately. Could I instead go +/- 3? I then got double root of two. But my book says the

    asked on October 14, 2009
  57. just a ?

    What do you think about this" Tragedy of the Commons" Idea? Have you ever found yourself saying these same things? r witnessed someone else behaving this way?

    asked on July 4, 2009
  58. math

    A fitness company surveyed the weights of its 90 costumers. Assume that the weights are normally distrubted with a mean of 162 lbs and a standard deviation of 3.5 lbs. If you select one of its costumers randomly, what is the probability that the costumer's

    asked on November 14, 2008
  59. Algebra 2

    What is the determinant of -2 -3 5 0 15 How you get 15 Use the definition of a determinant. From the first column you take take the element that is in the position of a permutation of 1, from the second you take the element that is in the position given by

    asked on February 6, 2007
  60. Science

    Suppose you are pulling a wagon with th handle at an can you make your task easier

    asked on January 29, 2017
  61. Math fractions

    A picture frame is 6 1/4 inches wide by 8 inches tall. If a 5 inch by 7 inch picture is to be centered in the frame, what should the right margin be?

    asked on November 19, 2015
  62. math

    If someone had a score of 495/500, What is the mixed number fraction? "I'm confused because if the denominator is bigger than the numerator how can we end up with a mixed number"

    asked on November 14, 2015
  63. Bus 101

    Can someone help me to compare answer for final exams introduction to Business - These are my answers Here are my answers... 1.c 2.a 3.a 4.d 5.c 6.b 7.a 8.b 9.c 10.b 11.a 12.a 13.c 14.d 15.a 16.a 17.a 18.8 19.c 20.b 21.a 22.a 23.d 24.a 25.b 26.d 27.a 28.b

    asked on April 7, 2015
  64. Physics

    A block of mass m = 2.4 kg is released from rest at a height of H = 3.0 m on a curved frictionless ramp. At the foot of the ramp is a spring whose spring constant is k = 317.0 N/m. What is the maximum compression of the spring, x?

    asked on June 17, 2014
  65. Chemistry

    Calculate the energy associated with the photon that would be released when an H electron falls fro the n=3 energy level to the n=1 energy level. show work if possible so I can understand how to do it. Thanks in advance!!!

    asked on March 31, 2014
  66. Math

    what is the surface area of a sphere with a radius of 4.75 units

    asked on June 12, 2013
  67. Algebra

    F) Why is (3x + 5) (x - 2) + (2x - 3) (x - 2) not in factored form? What is the correct final factored form? What is this factoring method called?

    asked on July 9, 2010
  68. Algebra

    4. A customer wants to make a teepee in his backyard for his children. He plans to use lengths of PVC plumbing pipe for the supports on the teepee, and he wants the teepee to be 12 feet across and 8 feet tall (see figure). How long should the pieces of PVC

    asked on July 4, 2010
  69. Algebra

    I'm not sure how to factor x^3-4x is greater than/equal to 0 so that I can find the zeroes. Can you demonstrate, please?

    asked on October 14, 2009
  70. science

    under what circumstances, is it okay to exploit natural area resources for human benefit?

    asked on July 3, 2009
  71. science

    Say you have a million dollars that you can invest into a bank account for 10% interest each year. how much money will you have each year to live off of? If you use more than amount,what happens to your original capital? What happens to your

    asked on June 30, 2009
  72. Science

    I need help to put a terrestrial resource plan together. I have no clue as where to start.

    asked on June 28, 2009
  73. math

    In the set of numbers 2,3,5,7,7,8,10 what is a) the arithmatic mean b) the harmonic mean c) geometric mean

    asked on November 14, 2008
  74. Math

    What is the answear to add. 5. 5/8 7. 2/3 19. 3/4

    asked on July 20, 2008
  75. precalc

    simplify: (x^-2 - y^-2) / (x^-1 - y^-1) i know you have to get rid of the negative powers, but i cant figure out how, any help?

    asked on February 16, 2008
  76. pre calc

    sketch the graph y=abs(x)+2 then sketch over the y=x line.

    asked on February 11, 2008
  77. research paper

    i have to include these questions in my report, and i can't seem to find them anywhere, any help? What influences may China and India have on other Asian countries as their economies begin to emerge on the global scene? What benefits have American

    asked on February 10, 2008
  78. math

    solve the inequality: n^3-7n+6

    asked on January 27, 2008
  79. Science

    How do i find the valence electron for Chlorine.

    asked on October 22, 2007
  80. science/chemistry

    thank you! What is the molar concentration of hydroxide ions in a solution with a pH of 6? Find the concentration of H ions first.. [H+]= antilog -ph Then, find [OH-] [OH-]= 1*10^-14/[H+]

    asked on June 5, 2007
  81. trig...again

    gahh i cant figure this one out either. you have you verify the identity only using one side of the equation: sec^2x*sin^2x+sec^2x=-1 this identity cannot possible be true. on the left side you are adding 2 squared quantities, how can that result be

    asked on May 7, 2007
  82. Science/Chemistry

    How many electrons can occupy a single molecular orbital? and Alumimum is a group 3A metal, Which ion does A1 typically form? I'm thinking Al3+ Your first question depends on the molecule involved and how it is bonded. Hybrid molecular orbits can be

    asked on January 10, 2007
  83. English

    I am having trouble with an analysis of “There is a beauty at the goal of life” I am needing help in identifying the speaker, basic situation and though development, mood, tone, and theme or universal truth.

    asked on December 12, 2017
  84. math

    if $13.69 is the price of a pair of sneakers after 75% was taken off, what was the original price of the sneakers?

    asked on February 11, 2015
  85. math

    If my dog and cat has a combine weight of 24kg and my rabbit and my dog has a combine weight of 20kg and my cat and rabbit has a combine weight of 10kg.whats the combine weight of my rabbit,dog and cat

    asked on June 22, 2014
  86. spanish

    if someone could help me conjugate these words correctly id really appreciate it!(sorry, I was unable to put accentos) 1. ?Habra alguien que me (comprender)? 2. Querian que tu (ir) a la biblioteca. 3. Tomas fue a la carcel porque (robar)a alguien. 4. Era

    asked on April 2, 2014
  87. health & safety

    Serious violations were issued citing 29 CFR 1910.252(a)(2)(iii)(B) and 1910.252(b)(2)(i)(A). Using the PDCA framework, develop a plan that will correct the deficiencies and ensure that the violations do not recur.

    asked on July 30, 2013
  88. math

    (8 x____) x 5 = 8 x ( 20 x 5).. third grade question please help me solve

    asked on January 5, 2013
  89. medical

    a. xenology b. morphology c. xenomorphology d.monumentology Which one of the above answers are the study of the form of body parts is called?

    asked on July 9, 2012
  90. Math

    Solve for x: x^2 -2x-4=0

    asked on April 29, 2012
  91. Math

    Pat paid $35 for a shirt that originally cost $50. What percent of the original price did the shirt cost? Please show working. I calculated it to be 30% but the answers provided are (a) 40% (b) 65% (c) 70% (d) 85%.........Please Help me

    asked on February 3, 2012
  92. math

    A test has 125 items. Each correct answer earns 1point and 65 percent is a passing grade. If you get 42 answers wrong will you pass? Show working

    asked on January 31, 2012
  93. Geometry

    A kite has diagonals of 16 inches and 23 inches as seen below. What is the perimeter of the kite?

    asked on March 15, 2011
  94. Science

    I have to make a book about Potassium. What are some cool wasy a can make a book from scratch?

    asked on October 23, 2010
  95. algebra

    How do you factor 2w^2+11w-30 ???

    asked on August 22, 2010
  96. Algebra

    2. Biologists want to set up a station to test alligators in the lake for West Nile Virus. Suppose that the costs for such a station are $2,500 for setup costs and $3.00 to administer each test. a. Write an expression that gives the total cost to test x

    asked on July 13, 2010
  97. Algebra

    1. The cost, in millions of dollars, to remove x % of pollution in a lake modeled by a. What is the cost to remove 75% of the pollutant? b. What is the cost to remove 90% of the pollutant? c. What is the cost to remove 99% of the pollutant? d. For what

    asked on July 13, 2010
  98. 5th grade

    sometimes called the simplepredicate.

    asked on March 30, 2010
  99. Algebra

    M is 5 years older than N. The product of their ages is 84. How old is M?

    asked on November 22, 2009
  100. Algebra

    I'm trying to solve x^3-3x^2-x+3 is less than zero. Except, I'm not sure how to factor it. I tried splitting it so that 3 would be a factor for 3x^2 and 3, so the result was 3(-x^2+1), and x^2 was a factor for x^3 and -3x^2, resulting in x^2(x+3). But this

    asked on October 14, 2009


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