# a

Most popular questions and responses by a-
## ALGEBRA CHECK ANSWERS

Solve each equation by graphing the related function. If the equation has no real-number solution, write no solution. NOTE: when I write + it has a minus on the bottom too x^2+7=0 a. x= +7 b. x = +3.5 c. x= 0 d. no solution *** 3x^2=0 a. +3 b. +1/3 c. 0

*asked on April 4, 2017* -
## statistics

In the game of roulette, a wheel consists of 38 slots numbered 0, 00, 1, 2,..., 36. To play the game, a metal ball is spun around the wheel and is allowed to fall into one of the numbered slots. If the number of the slot the ball falls into

*asked on October 11, 2017* -
## probability

The lifetime of a type-A bulb is exponentially distributed with parameter λ. The lifetime of a type-B bulb is exponentially distributed with parameter μ, where μ>λ>0. You have a box full of lightbulbs of the same type, and you would like to know

*asked on April 3, 2014* -
## Math

Write a ratio for the situation in three ways, comparing the first quantity to the second quantity. A zoo has 19 monkeys and 10 chimpanzees. 19 to 10, 19:10, (This) 10 to 29, 10:29, 19 to 29, 19:29, 10 to 19, 10:19, Write three ratios equal to 5/40. 2/14,

*asked on January 10, 2013* -
## Probability

Let Θ be a Bernoulli random variable that indicates which one of two hypotheses is true, and let P(Θ=1)=p. Under the hypothesis Θ=0, the random variable X is uniformly distributed over the interval [0,1]. Under the alternative hypothesis Θ=1, the PDF

*asked on April 2, 2014* -
## phy

A blue ball is thrown upward with an initial speed of 20.6 m/s, from a height of 0.8 meters above the ground. 2.5 seconds after the blue ball is thrown, a red ball is thrown down with an initial speed of 8.2 m/s from a height of 23.7 meters above the

*asked on September 13, 2011* -
## Physics

An arrow is shot from a height of 1.4 m toward a cliff of height H. It is shot with a velocity of 28 m/s at an angle of 60° above the horizontal. It lands on the top edge of the cliff 3.6 s later. a) What is the height of the cliff (in m)? I got 25.191 m

*asked on September 23, 2016* -
## math percent

Find the percent of markup. Round to the nearest tenth $31.00 to $35.00

*asked on December 18, 2015* -
## Probability

The random variable X is uniformly distributed over the interval [θ,2θ]. The parameter θ is unknown and is modeled as the value of a continuous random variable Θ, uniformly distributed between zero and one. Given an observation x of X, find the

*asked on April 3, 2014* -
## Probability

A defective coin minting machine produces coins whose probability of Heads is a random variable Q with PDF fQ(q)={3q2,0,if q∈[0,1],otherwise. A coin produced by this machine is tossed repeatedly, with successive tosses assumed to be independent. Let A be

*asked on April 2, 2014* -
## Probability

Alice has two coins. The probability of Heads for the first coin is 1/3, and the probability of Heads for the second is 2/3. Other than this difference, the coins are indistinguishable. Alice chooses one of the coins at random and sends it to Bob. The

*asked on April 2, 2014* -
## SS

The political movement that brought Africans together in the 1950s was known as ________. a. imperialism b. salt trade c. colonialism d. Pan-Africanism Enslaved Africans from West Africa traveled across the Atlantic Ocean to European Colonies in the

*asked on September 29, 2013* -
## Probability

We have k coins. The probability of Heads is the same for each coin and is the realized value q of a random variable Q that is uniformly distributed on [0,1]. We assume that conditioned on Q=q, all coin tosses are independent. Let Ti be the number of

*asked on April 3, 2014* -
## probability

The vertical coordinate (“height") of an object in free fall is described by an equation of the form x(t)=θ0+θ1t+θ2t2, where θ0, θ1, and θ2 are some parameters and t stands for time. At certain times t1,…,tn, we make noisy observations Y1,…,Yn,

*asked on April 2, 2014* -
## Probability

Let U, V, and W be independent standard normal random variables (that is, independent normal random variables, each with mean 0 and variance 1), and let X=3U+4V and Y=U+W. Give a numerical answer for each part below. You may want to refer to the standard

*asked on April 20, 2014* -
## math

A parking lot space is in the shape of a rectangle. If the space has a length of 23 feet and a width of 12 feet, what is the area of the parking space?

*asked on February 14, 2018* -
## Probability

Let X=U+W with E[U]=m, var(U)=v, E[W]=0, and var(W)=h. Assume that U and W are independent. The LLMS estimator of U based on X is of the form U^=a+bX. Find a and b. Express your answers in terms of m, v, and h using standard notation. a=- unanswered b=-

*asked on April 3, 2014* -
## physics

Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 4.6 m/s2 for 4.4 seconds. It then continues at a constant speed for 8.5 seconds, before applying the

*asked on September 13, 2011* -
## math

A hot water heater measures 20" in diameter. What is the area of a metal base for the water heater, assuming a four-inch overhang for the base beyond the edge of the heater? (Round to the nearest tenth.)

*asked on May 28, 2013* -
## Life Span Development

1. Levels of social cognitive __________ do not always match __________. A. reasoning / behavior B. attributions / behavior C. behavior / biases D. attributions / reasoning

*asked on January 6, 2017* -
## calculus2

A tank is full of water. Find the work required to pump the water out of the spout. (Use 9.8 m/s^2 for g. Use 1000 kg/m^3 as the density of water. Assume r = 9 m and h = 3 m.) The tank is a spherical shape with r as the radius(9m). On top of the tank is a

*asked on June 28, 2018* -
## Probability

Let N be a geometric r.v. with mean 1/p; let A1,A2,… be a sequence of i.i.d. random variables, all independent of N, with mean 1 and variance 1; let B1,B2,… be another sequence of i.i.d. random variable, all independent of N and of A1,A2,…, also with

*asked on April 3, 2014* -
## Probability

Consider a Poisson process with rate λ. Let N be the number of arrivals in (0,t] and M be the number of arrivals in (0,t+s], where t>0,s≥0. In each part below, your answers will be algebraic expressions in terms of λ,t,s,m and/or n. Enter 'lambda' for

*asked on May 1, 2014* -
## la

chose the meaning that best matches the word in italics. many actors avoid playing superheroes because they fear the ********stereotype******** that comes with success in the role. a label b popularity c persona d restrictions

*asked on December 22, 2015* -
## Calculus

Find the surface area of the part of the sphere x2+y2+z2=81 that lies above the cone z=√(x2+y2)

*asked on December 6, 2015* -
## Calculus

The total stopping distance T of a vehicle is shown below, where T is in feet and x is the speed in miles per hour. T = 2.5x + 0.5x^2 Approximate the change and percent change in total stopping distance as speed changes from x = 15 to x = 18 miles per

*asked on March 3, 2018* -
## Probability

Let T1,T2,…,Tn be i.i.d. observations, each drawn from a common normal distribution with mean zero. With probability 1/2 this normal distribution has variance 1, and with probability 1/2 it has variance 4. Based on the observed values t1,t2,…,tn, we

*asked on April 2, 2014* -
## Probability

For each of the following sequences, determine the value to which it converges in probability. (a) Let X1,X2,… be independent continuous random variables, each uniformly distributed between −1 and 1. Let Ui=X1+X2+⋯+Xii,i=1,2,…. What value does the

*asked on April 23, 2014* -
## physics

An electron experiences an electric force of 0.70 nN . What’s the field strength at its location?

*asked on March 3, 2018* -
## Probability

For any given flight, an airline tries to sell as many tickets as possible. Suppose that on average, 10% of ticket holders fail to show up, all independent of one another. Knowing this, an airline will sell more tickets than there are seats available

*asked on April 23, 2014* -
## Math

Yin's cellphone plan costs $30 a month. She used 12.5 hours in May. What was her cost per minute? About how many call can she make? Yin's average call lasted 3.25 minutes. How much did an average call cost?

*asked on January 29, 2016* -
## Statistics

Problem 6 A histogram shows the number of hours students spent preparing for a test. The table below gives the intervals and the heights of the bars (in percent per hour). Intervals contain the left endpoint but not the right. No student spent 25 hours or

*asked on February 25, 2013* -
## Social Studies

Compare and contrast the treatment of different religions by rulers of the Arab empire.

*asked on January 24, 2019* -
## Calculus

Sketch the vector field F⃗ (r⃗ )=2r⃗ in the plane, where r⃗ =⟨x,y⟩. Select all that apply. A.All the vectors point away from the origin. B. The vectors increase in length as you move away from the origin. C. All the vectors point toward the

*asked on October 10, 2015* -
## Calculus

For the vector field G⃗ =(yexy+3cos(3x+y))i⃗ +(xexy+cos(3x+y))j⃗ , find the line integral of G⃗ along the curve C from the origin along the x-axis to the point (3,0) and then counterclockwise around the circumference of the circle x2+y2=9 to the

*asked on November 20, 2015* -
## Probability

We are given the following statistics about the number of children in the families of a small village. There are 100 families: 10 families have no children, 40 families have 1 child each, 30 families have 2 children each, 10 families have 3 each, and 10

*asked on May 1, 2014* -
## physics

he index of refraction of crown glass is 1.53 for violet light, and it is 1.51 for red light. (a) What is the speed of violet light in crown glass? (b) What is the speed of red light in crown glass?

*asked on May 14, 2013* -
## college physics

If the amplitude of a sound wave is tripled, A.) by what factor will the intensity increase? B.) by how many dB will the sound level increase?

*asked on May 6, 2010* -
## physics

A white-crowned sparrow flying horizontally with a speed of 1.65 m/s folds its wings and begins to drop in free fall. (a) How far does the sparrow fall after traveling a horizontal distance of 0.550 m? (b) If the sparrow's initial speed is increased, does

*asked on April 18, 2012* -
## math

An object is launched at 19.6 m/s from a 58.8 m tall platform. The equation for the object's height above the ground (y) at time tseconds is y = –4.9t2 + 19.6t + 58.8 Use the quadratic formula to find the roots of this equation. What do these numbers

*asked on March 6, 2019* -
## math

A man makes a simple discount note with a face value of $2,200, a term of 140 days, and a 9% discount rate. Find the discount.

*asked on May 16, 2015* -
## Physics

Similarities between distance and displacement similarities between speed and velocity

*asked on February 18, 2014* -
## chemistry

A 8.50-g sample of solid AlCl3·6H2O was heated such that the water turned to steam and was driven off. Assuming ideal behavior, what volume would that steam occupy at 1.00 atm and 100.0 °C?

*asked on September 27, 2014* -
## math

d = 0.08t^2 - 1.6t + 9 A student stands facing a motion detector. He quickly walks toward the detector, slows down, stops and then slowly walks away from the detector. He speeds up as he gets farther away from the detector. When is the student closest to

*asked on March 7, 2019* -
## math

the amount of jens month phone bill is normally distributed with a mean of $69 and a standard deviation of $10. what is 68.26% of phone bill between?

*asked on December 3, 2015* -
## la

The speaker in "Birches" compares the boy's climbing to a. girls dying there hair b. sweeping up broken glass c. a forest full of spiderwebs d. filling a cup to the top I think D

*asked on September 17, 2017* -
## Trigonometry

Point P is located at the intersection of the unit circle and the terminal side of angle theta in standard position. Find the coordinates of P to the nearest thousandth. theta = -105degrees Please explain the steps. I'm completely stuck.

*asked on June 1, 2017* -
## calculus2

A manufacturer of corrugated metal roofing wants to produce panels that are u = 48 in. wide and 2 in. thick by processing flat sheets of metal as shown in the figure. The profile of the roofing takes the shape of a sine wave with equation y = sin(πx/12).

*asked on July 21, 2018* -
## Probability

In parts 1, 3, 4, and 5 below, your answers will be algebraic expressions. Enter 'lambda' for λ and 'mu' for μ. Follow standard notation. Shuttles bound for Boston depart from New York every hour on the hour (e.g., at exactly one o'clock, two o'clock,

*asked on April 30, 2014* -
## AlgebraII

A bag contains 5 pictures of Paris and 7 pictures of London. Determine whether the events of selecting the picture of London and another picture of London with replacement is independent or dependent. Then identify the indicated probability.

*asked on April 9, 2012* -
## math

For what value of k does the equation x2 + kx + 9have: Two distinct real roots One real root No real root

*asked on March 6, 2019* -
## Probability

Let Θ be an unknown random variable that we wish to estimate. It has a prior distribution with mean 1 and variance 2. Let W be a noise term, another unknown random variable with mean 3 and variance 5. Assume that Θ and W are independent. We have two

*asked on April 20, 2014* -
## Social Studies

How did the end of world war 2 impact Minnesota's economy? How did the GI Bill help encourage economic growth in Minnesota and the rest pf the naiton? How are the growth of highways and suburbs related?

*asked on April 30, 2018* -
## J

the decimal expansion of 147/120 will be terminate after how many decimal

*asked on September 12, 2016* -
## Chem

A dilute aqueous solution of Na2SO4 is electrolyzed between Pt electrodes for 3.70 h with a current of 2.77 A . Part A What volume of gas, saturated with water vapor at 25∘C and at a total pressure of 742 mmHg , would be collected at the anode? The vapor

*asked on March 31, 2018* -
## Math

In an examination of a certain class, at least 70% of the students failed in Physics, at least 72% failed in Chemistry, at least 80% failed in Mathematics and at least 85% failed in English. How many at lest must have failed in all the four subjects ?

*asked on May 26, 2017* -
## Geometry Ratios

At the half time show during a football game, a marching band is to form a rectangle 50yards by 16yards. The conductor wants to plan out the band members positions using a 14- by 8.5-in. sheet of paper. What scale should she use to fir both dimensions of

*asked on March 13, 2012* -
## chemistry

What is the Na+ concentration of 2.85 M sodium sulfate?

*asked on October 10, 2010* -
## chemistry

Hydrogen gas produced by this reaction is typically collected via water displacement, during which time the hydrogen gas becomes saturated with water vapor. If 238.4 mL of gas with a total pressure 1.27 atm was collected via water displacement at 29.4 °C,

*asked on September 27, 2014* -
## chemistry

Air is 78.1% nitrogen, 20.9% oxygen, and 0.934% argon by moles. What is the density of air at 22 °C and 760 torr? Assume ideal behavior.

*asked on September 27, 2014* -
## Algebra2

how do you solve this? A dice is rolled twice. What is the probability of getting a multiple of 3 on the first roll or a total of 7?

*asked on April 10, 2012* -
## math

The graph of y = –3sin (2x) is shifted to the left by 30° units and up 5 units. Write the new equation. My answer y= -3sin (2x- 30°) +5 Is this correct?

*asked on April 15, 2019* -
## chemistry

Imagine there is a tank of unknown gas that contains 53.31% carbon, 35.51% oxygen, and 11.18% hydrogen by mass. At 35.0 °C and 0.470 bar, 2.0 L of the gas has a mass of 3.3 g. Using this information, answer the following questions. a.) What is the

*asked on September 27, 2014* -
## Math

What is the simplified version of this expression 28st/-4t the / meaning its a fraction

*asked on September 21, 2018* -
## History

What impact did imperial Spain have on the Americas? Spanish culture came to dominate and replace native cultures. Local leaders were replaced by Spanish parliamentary assemblies. Financing from Spain started the industrialization of the Americas.

*asked on August 3, 2018* -
## physics

an 85.0kg mountaineer remains in equilibrium while climbing a vertical cliff. the tension force in the supporting rope is 745 N. Find the magnitude of the reaction force F, which the cliff exerts on the mountaineer's feet.

*asked on October 3, 2017* -
## Business Math - help needed

Federal Express bought material handling equipment for its hub operations that cost $180,000. Using the MACRS, what is the depreciation expense in year 3 (using a five-year class)? A. $43,560 B. $34,560 C. $15,360 D. $40,000 Answer: B??

*asked on April 10, 2016* -
## math

a man gets an invoice for $460 with terms 2/10, 1/15, n28 ow much would he pay 25 after the invoice date? help a little confused?

*asked on April 22, 2015* -
## calculus

A small aircraft, on a heading of 225 degrees, is cruising at 150 km/h. It is encountering a wind blowing from a bearing of 315 degrees at 35 km/h. Determine the aircraft's ground velocity.

*asked on May 2, 2010* -
## Chemistry

In a gaseous system at equilibrium with its surroundings, as molecules of A(g) collide with molecules of B(g) without reacting, the total energy of the gaseious system 1. decreases 2. increases 3. remains the same

*asked on April 13, 2009* -
## Managerial Economics

Economists consider which of the following costs to be irrelevant to a short run business decision? A)out of pocket B)historical cost C)opportunity cost D)replacement cost

*asked on November 12, 2007* -
## chemistry

Ka for hypochlorous acid, HClO, is 3.0*10^(-8). Calculate the pH after 10.0, 20.0, 30.0, and 40.0 mL of 0.100M NaOH have been added to 40.00mL of 0.100M HClO.

*asked on March 10, 2011* -
## Managerial Economics

Diseconomies of scale can be caused by: A)bureaucratic inefficiencies B)increasing advertising and promotional costs. C)the law of diminishing returns D)all of the above

*asked on November 12, 2007* -
## physics

A child of mass 54.7 kg sits on the edge of a merry-go-round with radius 2.3 m and moment of inertia 222.81 kgm2. The merrygo-round rotates with an angular velocity of 1.6 rad/s. What radial force does the child have to exert to stay on the merry-go-round?

*asked on March 29, 2016* -
## English

If you guys were trying to survive the Titanic How do you think you would feel? How would you react? What would you do to secure your survival?

*asked on January 14, 2019* -
## Probability

A single dot is placed on a very long length of yarn at the textile mill. The yarn is then cut into pieces. The lengths of the different pieces are independent, and the length of each piece is distributed according to the same PDF fX(x). Let R be the

*asked on May 1, 2014* -
## Science

Acetaldehyde, CH3CHO, will decompose into methane and carbon monoxide according to CH3CHO (g) -> CH4 (g) + CO (g) At 450C the rate of consumption of CH3CHO is measured to vary with the concetration of CH3CHO raised to the power 1.5. With a CH3CHO

*asked on April 28, 2013* -
## Chemistry

For ethanol, C2H5OH, which is mixed with gasoline to make the fuel gasohol, H°f = -277.63 kJ/mol. Based upon data in Table 6.2, and that the density of ethanol is 0.787 g•cm-3, the number of kilojoules released by burning completely 2.40 gallons of

*asked on October 16, 2011* -
## PHYSICS

A 2000kg elevator is attached to a 1800kg counterweight. What power must the motor supply to raise the elevator at 0.4m/s?

*asked on April 12, 2016* -
## Calculus

A company manufactures x units of one item and y units of another. The total cost in dollars, C, of producing these two items is approximated by the function C=7x^2+xy+1y^2+600. A) If the production quota for the total number of items (both types combined)

*asked on October 18, 2015* -
## physics

The drawing below shows a person who, starting from rest at the top of a cliff, swings down at the end of a rope, releases it, and falls into the water below. There are two paths by which the person can enter the water. Suppose he enters the water at a

*asked on February 22, 2013* -
## science

A small hockey puck slides without friction over the icy hill and lands 6.20 m from the foot of the cliff with no air resistance.What is its initial speed v0 at the bottom of the hill?

*asked on September 27, 2012* -
## math

Find the domain and range of the function y= -3(x-1/3)^2+4/3

*asked on March 4, 2019* -
## trig

Describe how the graphs of y + 3 = 2sin (3x + 90°) compares to the graph of y = sin (x).

*asked on April 16, 2019* -
## Civics

In what way do mixed and market economies support the ideals of democracy? A. Mixed and market economies elect a few farmers and local leaders to choose which goods and services to produce. B. Mixed and market economies do not produce more goods or

*asked on May 19, 2016* -
## Probability

All ships travel at the same speed through a wide canal. Each ship takes t days to traverse the length of the canal. Eastbound ships (i.e., ships traveling east) arrive as a Poisson process with an arrival rate of λE ships per day. Westbound ships (i.e.,

*asked on April 30, 2014* -
## Physics Help Please

A sample of an unknown material appears to weigh 270 N in air and 165 N when immersed in alcohol of specific gravity 0.700. (a) What is the volume of the material? (b) What is the density of the material?

*asked on November 12, 2010* -
## math

Is my answer correct? Write this quadratic function in the vertex form y = 4(x+5)(x-2) = 4(x² + 3x - 10) = 4(x² + 3x + 9/4 - 10 - 9/4) = 4(x² + 3x + 9/4) - 49 = 4(x+3/2)² - 49 Ans: y = 4(x+3/2)² - 49 Vertex = (-3/2, -49)

*asked on March 4, 2019* -
## Trig/pre-calc

r=8cos(theta)+5sin(theta), convert the polar equation into a rectangular equation and then complete the square and determine the center radius...? Help?! I missed the section, and am not getting anywhere with the text...

*asked on August 12, 2011* -
## math

D = 0.08t^2 - 1.6t + 9 Why does this equation above fits this model: A student stands facing a motion detector. He quickly walks toward the detector, slows down, stops and then slowly walks away from the detector. He speeds up as he gets farther away from

*asked on March 7, 2019* -
## Math

-4/10x -9 < 9/10 = x < 24 3/4 Did I do this right? was solving for the inequality and the -4/10x is together.

*asked on November 1, 2018* -
## Civics

Pedro is thinking about buying U.S. savings bonds. However, there is a financial institution controlled by the government that may actively discourage Pedro from buying bonds. How and why would such a financial institution do this? A. Stocks on Wall Street

*asked on May 19, 2016* -
## Probability

Suppose that you have two laptops, both of which you begin using at time 0. Each laptop will eventually fail, and we model each one's lifetime as exponentially distributed with the same parameter λ. The lifetimes of the two laptops are independent. One of

*asked on April 30, 2014* -
## PHYSICS HELP

A 320-N sphere 0.20 m in radius rolls without slipping 6.0 m down a ramp that is inclined at 25° with the horizontal. What is the angular speed of the sphere at the bottom of the slope if it starts from rest?

*asked on November 3, 2010* -
## politics

Why is free health care important in a democratic society?

*asked on February 28, 2019* -
## Math

Simplify, stating any restrictions on the variables: a. 18a^6bc^7d^3/ 12a^2b^4c^7d b.x^2+5x+6/x^2-2x-15 c. 6y^2-96/2y^2+18y+40

*asked on February 22, 2019* -
## chem TITRATION

1. If a student fails to remove a large air bubble in the buret before beginning the titration, what will be the effect on the volume of titrant required to reach the titration endpoint? A. The student will record a volume that is SMALLER than it should be

*asked on May 25, 2018* -
## math

Write this equation in the vertex form: y= -3x^+2x+1

*asked on March 2, 2019* -
## math

a man holds a note of $6,000 that has an interest rate of 13% annually the note was made on march 17 and is due november 11 he sells the note to a bank on june 14 at a discount rate of 12% annually find the proceeds on the third-party discount rate. Ok now

*asked on May 16, 2015* -
## Probability

Let X be a continuous random variable. We know that it takes values between 0 and 3, but we do not know its distribution or its mean and variance. We are interested in estimating the mean of X, which we denote by h. We will use 1.5 as a conservative value

*asked on April 23, 2014*