Tuesday
May 31, 2016

# Posts by john

Total # Posts: 7,733

Basic Statistics
A researcher is interested in estimating the average salary of police officers in a large city. She wants to be 95% confident that her estimate is correct. If the standard deviation is \$1050,how large a sample is needed to get the desired information and to be accurate within...
October 15, 2014

Basic Statistics
A random sample of 16 mid-sized cars tested for fuel consumption gave a mean of 26.4 kilometers per litre with a standard deviation of 2.3 kilometers per litre. (a)Assuming that the kilometers per litre given by all mid-sized cars have a normal distribution,find a 99% ...
October 15, 2014

Statistics
The points of 100 children in a test are normally distributed with mean of 25 points and a standard deviation of 10 points. (a)Given that the passing mark is 20, estimate the number of children who passed the test. (b)If 5.59% of the children obtain a distinction by scoring x ...
October 15, 2014

Math
A water tank will be drained at a constant rate of 42.4 liters per hour starting at 9:00 A.M. After one hour, the change in the amount of water in the tank can be represented as –42.4. Which of the following represents the total change in the amount of water in the tank ...
October 14, 2014

math
how do i work this problem 8x25x23 using subtraction in mental math
October 14, 2014

physics
A truck with mass 2000 kg tows a boat and trailer of total mass 500 kg. The rolling coefficient of friction for the truck is 0.080 and for the trailer is 0.050. The force of the truck’s drive wheels pushing backward on the pavement is 3.0 kN. (a) Determine the ...
October 14, 2014

Math
If john makes 60 k a year , how much does he make each month?
October 14, 2014

Chemistry
Cambridge uses FA 1, FA 2 etc to name chemicals or solutions. What does FA stand for?
October 13, 2014

physics
Two crewmen pull a boat through a lock, as shown in Figure 5-25. One crewman pulls with a force of F1 = 155 N at an angle of θ = 32° relative to the forward direction of the raft. The second crewman, on the opposite side of the lock, pulls at an angle of 45°. With...
October 11, 2014

Physics
A pilot gets into trouble flying 2000m above the pacific ovean. He flies 550 km/h [S 30(degree)W] with a wind from the NW of 100 km/h. he ejects himself at a velocity of 10m/s [upwards]. What is his velocity at the instant he hits the ocean surface? Express your answer in km/h.
October 11, 2014

physicss
If there were no air resistance, with what speed would drops hit the Earth if they fell from a cloud 1980 m above the Earth’s sur- face? The acceleration of gravity is 10 m/s2
October 10, 2014

Physics
A toy gun uses a spring to shoot a ball with a mass of 5.0 g. The spring is “loaded” by compressing it 5.0 cm and has a spring constant of 288 N/m. The end of the spring is at the end of the gun (the ball does not travel any distance inside the gun after the spring) ...
October 10, 2014

Empirical Inquiry
Assume that true proportions of the people who support "Obamacare" is a quarter of the population. If you took a sample of 1,000 people living in the United States, what would be the variance of this estimator? what would be the expected value of your estimator for ...
October 9, 2014

Math
In this problem, what do you have to do because you just wrote something but didnt explain how this is suppose to be done
October 9, 2014

physics
im sorry but i cant tell you the answer ill be gladly to check though
October 9, 2014

math
2/5(x+3)=6 2/5x+6/5=6 5/2(2/5x) +6/5 = 6(5/2) X+6/5=15 X-6/5=15-6/5 X=
October 9, 2014

College Math
A block with a mass of m = 31 kg rests on a frictionless surface and is subject to two forces acting on it. The first force is directed in the negative x-direction with a magnitude of F1 = 11 N. The second has a magnitude of F2 = 22.75 N and acts on the body at an angle θ...
October 9, 2014

Pre-Calculus
October 8, 2014

Pre-Calculus
Some cowboys plan to build a rectangular corral in a canyon. They have 200 feet of fencing to use for three sides of the rectangle (the canyon wall is used for the 4th side). a) What is the maximum area that they can fence in? b) What are the dimensions of the rectangle?
October 8, 2014

science
A 3.70 L sample of neon at 11.24 atm is added to a 10.0 L cylinder that contains argon. If the pressure in the cylinder is 5.24 atm after the neon is added, what was the original pressure (in atm) of argon in the cylinder?
October 8, 2014

Math
For the most recent year available, the mean annual cost to attend a private university in the United States was \$20,082. Assume the distribution of annual costs follows the normal probability distribution and the standard deviation is \$4,500. Ninety-five percent of all ...
October 7, 2014

math
a fish tank that holds 80 gallons of water is 55 percent full how many gallons are in the tank now and how many more gallons are needed to fill the tank
October 7, 2014

clemson
A farmer wants to make three identical rectangular enclosures along a straight river, as in the diagram shown below. If he has 1680 yards of fence, and if the sides along the river need no fence, what should be the dimensions of each enclosure if the total area is to be ...
October 6, 2014

Math
A movie poster shows King Kong towering over an adult human. On the poster, King Kong measures 42cm, while the human measures 5 cm. How tall is King Kong supposed to be, to the nearest foot?
October 5, 2014

math
there are 32 boys and 24 girls. what re the various number of teams that can be made that would have the same number of boys and girls on each team?
October 5, 2014

physics
when the students place the unknown cart on the scale the scale reads the mass of 1.20 kg a)calculate the percent difference b) state the reason for the difference . explain
October 3, 2014

Math
Please check my answers I think they are right if not please tell me where I went wrong. Thanks The annual net income of general electric for the period 2007-2011 could be approximated by P(t) = 3t^2- 24t +59 billion dollars (2<t<6) where t is time in years. a) compute p...
October 2, 2014

AC DC Circuit fundamentals
If a 10k ohm and a 5k ohm resister are connected in series across a 12 volt source whats the voltage across the 10k ohm resistor and 5 ohm resistor?
October 2, 2014

Physics
A motor of a certain elevator gives it a constant upward acceleration of 0.767 m/s2, the elevator starts from rest, accelerates for 2s, then continues with a constant speed. a) What is his final speed after 2s? b) Calculate speed after 1 ,and 3 s.? c) How far has it risen 1,2,...
October 2, 2014

math
if total ticket sales were \$1625 adult tickets were \$7.00 and student tickets were \$3.00 and twice as many students bought tickets than adults, how many students and adult tickets were sold?
October 1, 2014

chemistry
A solution is prepared by placing 23.9 g of KCl in a 0.500 L volumetric flask and adding water to dissolve the solid, then filling the flask to the mark. What is the molarity of an AgNO3 solution if 27.9 mL of the KCl solution react exactly with 45.0 mL of the AgNO3 solution?
October 1, 2014

Fiancne
Stephenson Real Estate Company was founded 25 years ago by the current CEO, Robert Stephenson. The company purchases real estate, including land and buildings, and rents the property to tenants. The company has shown a profit every year for the past 18 years, and the ...
September 30, 2014

Physics
A lorry of mass 12,000kg traveling at a velocity of 15 m/s crashes into the back of a moving car of mass 1500kg, traveling at a velocity of 5 m/s. The vehicles move together after the impact. Calculate their velocity.
September 29, 2014

math
jocelyn got 19 correct answers out of 25 questions on her last test. What percent of the questions did she answer correctly?
September 28, 2014

Chemistry
What is the total ionic equation of this: 3CaCl2(aq) + 2K3PO4(aq) → Ca3(PO4)2(s) + 6KCl(aq) Shw all physical states of the reactants and products
September 26, 2014

Physics
4. A ball is kicked toward a fence from a point 32 meters away. The velocity of the ball as it leaves the kicker’s foot is 24 m/s at an angle of 37 degrees above the horizontal. The top of the fence is 2.0 meters high. Assuming air resistance to be negligible…(1 ...
September 25, 2014

Grammar
Sentence: I tried all of the natural remedies, such as dishwashing liquid, but the ants kept coming back. Is there a comma before "such as"
September 24, 2014

MATH
Estimate the indicated derivative by any method y=1-x^2 ; estimate dy/dx , x=-1 I know I would use the f(x)= f(x+H)-(x)/h I am a bit overwhelmed with what to do next. Thanks John
September 24, 2014

algebra
I invest a sum of money at 10% annual simple rate and twice that amount at 12% annual simple interest.My total yearly in come from both investment was \$2890,how much was invested at each rate? Also What is the speed of each train if one train travels 8 mph faster than the ...
September 24, 2014

English
What are all of the prepositional phrases in the following sentence: Ancestors, in every variety of dress, from the Elizabethian knight to the buck of the Regency, stared down and daunted us.
September 22, 2014

algebra
Thank You
September 22, 2014

algebra
a 25 inch piece of a steel rod is cut into 3 pieces so that the length of the second piece is twice the length of the first piece.The third piece is 1 inch longer than 5 times the length of the first piece.What are the lengths of the pieces
September 22, 2014

physics
A soccer ball is kicked horizontally from the edge of a 125 m high cliff with an initial speed of 15 m/s. At what horizontal distance does the ball land?
September 21, 2014

physics
A ball is thrown straight up into the air. At each of the following instants, is the magnitude of the ball's acceleration greater than g, equal to g, less than g, or zero? Air resistance may be neglected. A) just after leaving your hand? B) at the very top (maximum height...
September 21, 2014

Chemistry (Ionic Equilibria)
When a WEAK acid can be said to be weak, and when a WEAK acid can be said to be strong? I only know the difference between weak acids and strong acids, but i dont know that even weak acids can be classified as weak and strong. Plz help
September 21, 2014

Math
What is the largest possible value of the sum of 1000
September 19, 2014

Physics 12
A sports car is travelling along a highway at a constant velocity of 36 m/s [N] exceeding the speed limit. It passes an unmarked police car parked on the shoulder of the highway. The police car accelerates from rest, 3.0 s after the sports car passed it, at the rate of 6.0 m/...
September 18, 2014

Calculus
Calculate the average rate of change of the given function f over the intervals [a, a+h] where h=1, 0.1, 0.01, 0.001, and 0.0001. I have no clue how to do this. Any help would be appreciated. Thanks I know I use the formula f=f (a+h) - f (a)/h Then do I need to plug in the -2x...
September 16, 2014

trig
A planes actual resulting ground speed and direction are 550 mph and N26E. A wind is blowing from the northeast. If the pilot is holding a course of N27E how fast is the wind blowing I'm just stumped. It's an extra credit question is basically why I'm stumped.
September 16, 2014

Trig
A planes actual resulting ground speed and direction are 550 mph and N26E. A wind is blowing from the northeast. If the pilot is holding a course of N27E how fast is the wind blowing?
September 16, 2014

Sublette
An appellate court that hears an appeal on a money laundering case from a district court
September 16, 2014

can yiu help me with this asignment
September 15, 2014

chemistry
The ionic radii of Na+ (atomic weight 22.99) and Cl- (atomic weight 35.45) are 1.0 and 1.8 Angstrom, respectively. Treating the ions as hard spheres, calculate the density of NaCl. Compare this with the measured density of 2.17 g/cm3.
September 13, 2014

science
(1.b) Calculate your de Bröglie wavelength and momentum when you are driving a car at a speed of 104 km/hr (~65 mph), assuming your mass is 80 kg.
September 13, 2014

maths
An ant must walk from one vertex of a cube to the "opposite" vertex (that is, the vertex that is farthest from the starting vertex) and back again to its starting position. It may only walk along the edges of the cube. For the entire trip its path must traverse ...
September 12, 2014

math
Every marble in a jar has either a dot, a stripe or both. The ratio of striped marbles to non-striped marbles is 3:1, and the ratio of dotted marbles to non-dotted marbles is 2:3. If six marbles have both a dot and a stripe, how many marbles are there all together?
September 12, 2014

Math
14.4ft.
September 10, 2014

algebra
Solve F(x) for the given domain. Include all of your work in your final answer. Submit your solution. F(x) = x2 + 2 F(x + h) =
September 10, 2014

physics
Assume a projectile is launched from ground height over a flat plane, at an angle of 50 degrees above the horizontal with an initial speed of 100 m/s. What is the initial velocity of the projectile parallel to the ground (in the x direction) and perpendicular to the ground (in...
September 8, 2014

American History
The Whiskey Rebellion A. caused the formation of the Democratic Societies. B. unified northern merchants and southern farmers. C. led to the development of two distinct political groups. D. created a single party political system. C?
September 8, 2014

English
The military because they give up their lives to fight for us.
September 8, 2014

Physics
Two ping-pong balls each have a mass of (1.4x10^0) g and carry a net charge of (3.99x10^0) μC. One ball is held fixed. At what height should the second ball be placed directly above the fixed ball if it is to remain there?
September 7, 2014

physics
A spacecraft of mass 3.5 x 102kg was moving at 1.5 x 102ms-1 when its motor, operating at 8.4 x 102 kW fired for 5.0s Find the new velocity acquired by the spacecraft I dont know how to find the new velocity i found the work Power = w/t 840 x 5 = W 4200J = W Dont know what to ...
September 6, 2014

Physics
You toss a tennis ball straight upward. At the moment it leaves your hand it is at a height of 1.5 m above the ground, and it is moving at a speed of 8.0 m/s. (a) How much time does it take for the tennis ball to reach its maximum height? (b) What is the maximum height above ...
September 6, 2014

marketing
3. Now that we have discussed the concept of being customer oriented, let's discuss MARKETING ORIENTATION. Customer oriented practices are just one small piece of operating with a market orientation. Describe what market orientation means, and how you see that it differs ...
September 1, 2014

marketing
Many companies claim that they are customer-oriented, but their customer service leaves a lot to be desired. Why do you think this is the case?
September 1, 2014

marketing
How does the marketing relate to your own experiences and beliefs? Which information do you find particularly interesting and/or useful? Is there anything surprising to you in what you learned?
September 1, 2014

physics
Three point charges are fixed in place in a right triangle. What is the electric force on the q = -0.7 µC charge due to the other two charges? (Let Q1 = +0.79 µC and Q2 = +1.5 µC.)
September 1, 2014

English/Grammer
5. S/V/IO/DO 6. S/V/DO 8. S/V/IO/DO 9. S/V/IO/DO
August 31, 2014

English/Grammer
Can someone tell me if I did them correctly? 1. He followed the map to the treasure. 2. Darcy sang the song slowly. 3. They were certain about the time. 4. I called him a sucker. 5. I found the puppy a home. 6. He answered the question incorrectly. 7. The president gave the ...
August 31, 2014

Chemistry
new volume will be 1.440 + 0.567 in Litres or 1440 + 567 in mL
August 31, 2014

Chemistry
I am unsure how to write hypotheses for my experiments for pH, salinity using tirration(agno3), turbidity, conductivity of water samples. The teacher wants the hypothesis in this format Hypothesis format - If (relationship between independent variable and dependent variable) ...
August 31, 2014

Chemistry
What is the pH of a solution prepared by dissolving 1.23g of 2-nitrophenol (FM 139.11) in 0.250 L? Well so, i calculated the no.moles of 2-nitrophenol, and divided it by 0.250, to get the molarity which was 3.53E-2. Since the molar ratio of dissociation is 1:1, i assumed [H+] ...
August 31, 2014

math
1645; 1815
August 29, 2014

chemistry
a solution is prepared by mixing 1.0 grams of benzen(c6h6) in 100g of water to create a solution total volume of 100ml.calculate the molarity,mass percent,mole fraction and molarity of benzene in the solution
August 26, 2014

biochemistry
Calculate the mass of alanine and the volume of HCl required to prepare 1 litre of 0.1mol/litre buffer with pH of 2
August 24, 2014

english
August 23, 2014

Physics
Thank you :)
August 22, 2014

Physics
1.)A force of 250 is just sufficient to start a 50 kg steel trunk moving across a wooden floor. Find the coefficient of static friction. 2.) compute the acceleration of the block sliding down a 30 deg inclined plane if the coefficient of kinetic friction is 0.20.
August 22, 2014

logical and critical reasoning
Regardless of what Jim says, baseball is a more refined sport than ice hockey. This is so because more refined people watch baseball rather than ice hockey. You can tell which people are more refined simply by the fact that they prefer the more refined sport to the less ...
August 21, 2014

logical and critical reasoning
The second proposition is this: an action done from duty has its moral worth, not in the purpose that is to be attained by it, but in the maxim according to which the action is determined. The moral worth depends, therefore, not on the realization of the object of the action, ...
August 21, 2014

Math
I don't know how to answer this. If 10% of a number is 2 less than 20% of the same number, then 80% of the number equals_______.
August 21, 2014

biology
Bacteria, Plants
August 19, 2014

Algebra
To convert miles per hour to feet per second, which conversion factor would not be used? a. 1 hr/60 min b. 1 min/60 sec c. 5280 ft/1 mi d. 1 mi/5280 ft
August 19, 2014

Math
To convert miles per hour to feet per second, which conversion factor would not be used? a. 1 hr/60 min b. 1 min/60 sec c. 5280 ft/1 mi d. 1 mi/5280 ft
August 19, 2014

Math
HATS OFF ! Amazing is a less adjective for you. Thank you.
August 19, 2014

Math
The circumference of a circle is 4 times the circumference of a circle with a radius 1 unit less. What is the radius of each circle?
August 19, 2014

Math
AMAZING. Thanks Much.
August 19, 2014

Math
If the radius of a circle is increased by 1 unit, the area of the circle is increased by 16 pi square units. What is the radius of the original circle?
August 19, 2014

math
The point (-3,4) is on a circle with its center at the origin. Which of the following points must also be on the circle?
August 19, 2014

Trigonometry
Your horse on a merry-go-round is 18.3 m from the center. Suppose the merry-go-round makes 12.4 rev per ride. If you take 3 rides, through what angle do you move and how many meters do you travel?
August 15, 2014

Trigonometry
Your horse on a merry-go-round is 18.3 m from the center. Suppose the merry-go-round makes 12.4 rev per ride. If you take 3 rides, through what angle do you move and how many meters do you travel?
August 15, 2014