# Posts by katie

Total # Posts: 2,107

**statistics**

Let x be a continuous random variable that is normally distributed with a mean of 24 and a standard deviation of 7. Find the probability that x assumes a value between 27.5 and 59.0. Use Table IV in Appendix C to compute the probabilities. Round your answer to four decimal ...

**statistics**

Let x be a continuous random variable that is normally distributed with a mean of 65 and a standard deviation of 15. Find the probability that x assumes a value less than 45.

**statistics**

Find the area between x = 9.5 and x = 23 under a normal distribution curve with μ = 20 and σ = 4 .

**statistics**

Let x be a continuous random variable that is normally distributed with a mean of 65 and a standard deviation of 15. Find the probability that x assumes a value less than 44.

**6th grade math**

Find the sum of the angle in each regular polygon. (Pentagon)

**physics**

Using fn = (nv)/(2L) and plugging in values as fn = f6 = 557.14 = (6v)/(2*0.7) and solving for v, we get v = 130 m/s.

**physics**

Using fn = (nv)/(2L) and plugging in values as fn = f6 = 557.14 = (6v)/(2*0.7) and solving for v, we get v = 130 m/s.

**physics**

Prolonged exposure to sounds of intensities lower than the threshold of pain can also damage the ear. This is more dangerous since there is no pain to warn the victims about the ear damage and they can end up damaging their ears unknowingly through prolonged exposure to such ...

**physics**

(A) When only one end is open, it is a 'closed' pipe and so we use Where fn = frequency of nth harmonic (Hz) n = harmonic number v = speed of sound inside the pipe (m/s) L = length of pipe closed at one end (m) Plugging in the values and solving, we get f1 = 428.75 Hz ...

**Spanish-7th please check**

Did I answer these correctly? ¿Qué necesitas para jugar al tenis? Necesito una raqueta y una pelota de tenis para jugar al tenis. ¿Cuándo juegas el ajedrez? Yo juego el ajedrez por la noche.

**physics help**

I need help confirming my answers: 1) The work done on an electric charge equals a) IR b)q/t c)Vq d) It I think it's C.(Vq) 2) The direction of an electric field is the direction that a ___ test charge will move when placed in the field. a)negative b) positive c) neutral I...

**biomechanics**

If a soccor ball with a mass of 0.43 kg is kicked while it is in the air, with a force of 15 N oriented 32 degrees above the horizontal, what is the resultant acceleration?

**physics**

I need help confirming my answers: 1) The work done on an electric charge equals a) IR b)q/t c)Vq d) It I think it's C.(Vq) 2) The direction of an electric field is the direction that a ___ test charge will move when placed in the field. a)negative b) positive c) neutral I...

**Chemistry**

All of those are separate reactions that are being reacted with 50 mL of 1.50 M NH3.

**Chemistry**

How do you calculate the volumes of the acid solutions (1.50M HCl, 1.50M HNO3, and 1.50 M H2SO4?

**Math**

A circular garden has an area of 25π m2 If the . radius is increased by two meters, and fencing is sold only in one meter sections, how much fencing is needed to keep out the rabbits

**Chemistry**

Sorry my computer accidentally resent it!

**Chemistry**

Is a calibrated thermometer more precise than one that has not been calibrated? What implications does this have for measuring temperature changes as contrasted with measuring individual temperatures?

**Chemistry**

Is a calibrated thermometer more precise than one that has not been calibrated? What implications does this have for measuring temperature changes as contrasted with measuring individual temperatures?

**MATH**

Method 1 Simply list the multiples of each number (multiply by 2, 3, 4, etc.) then look for the smallest number that appears in each list. Example: Find the least common multiple for 5, 6, and 15. First we list the multiples of each number. Multiples of 5 are 10, 15, 20, 25, ...

**chemistry**

A scientist wants to make a solution of tribasic sodium phosphate, \rm Na_3PO_4, for a laboratory experiment. How many grams of \rm Na_3PO_4 will be needed to produce 250 mL of a solution that has a concentration of \rm Na^+ ions of 0.600 \it M?

**Chemistry**

Would you use q/mass*change in T= c so 1930J/(500g*10degC)=.386J/degC?

**Chemistry**

An unknown material absorbs 1,930 J of heat when it changes from 25 °C to 35°C. The sample weighs 500g. What is the specific heat of this material?

**Math**

After the first 41 games of the baseball season, the Red Sox have a winning percentage of 0.585 and the Yankees have 0.512. How many games behind the Red Sox are the Yankees?

**math**

so there be 25 green, 15 blue, 10 red???

**math**

TODAY

**chemistry**

write an equilibrium constant expression for the reaction of acetylene gas with hydrogen gas to produce methane gas.

**algebra**

A set of 2 similar triangles was drawn in a design. One of the triangles was ½ of the other. If the measures of the smaller triangle were 5, 7, and 12 cm, the measures of the larger triangle = 10,14 and 20 cm. true or false

**Geometry quick i have test tomorrow**

what is the length of any diagonal of a regular pentagon with a side of 20mm

**geometry**

what is the length of any diagonal of a regular pentagon with a side of 20mm ?

**Chemistry**

How do i determine the exact molarity of .2 M of HCL? The molarity of NaOH Used was .2010M used in the titration. And the volume used 10.33 mL used to reach equivalence point. What would be the Molarity of HCL?

**math**

if less then a half of a garden is planted with corn is it a reasonable to estimate that 2-3rds of the garden is planted with corn?

**chemistry**

If 74.5 grams of a hot metal was added to 56.4 grams of water and the temperature of the water rose from 20.4 to 33.4 degrees, how many KJ of energy was lost by the hot metal? i need helping setting up where the numbers go. I'm lost

**chemistry**

i need help setting this problem up. i don't understand which numbers go where

**chemistry**

If 74.5 grams of a hot metal was added to 56.4 grams of water and the temperature of the water rose from 20.4 to 33.4 degrees, how many KJ of energy was lost by the hot metal?

**Differential equation- Math**

Find the general solution of the following system of equation? Please help, i don't know what to do... dx/dt = 3x +2y +2z dy/dt = -5x - 4y - 2z dz/dt = 5x + 5y +3z.

**amet**

substituting t=12s gives a = 2(12) - 10 = 14m/s-2 Using the formula d = Vit +1/2 at^2 d = 15(12) + 0.5 (14)12^2 d = 180 + 1008 d = 1188 meters (distance traveled) add the initial position d = 1188 + 1.8 = 1189.8 (Position of particle) I hope this is correct... :(

**social studies**

it say to briefly describe the events that followed the Confederate defeat at Gettysburg. (civil war). first is followed meaning before or after. and what does it mean by describe the events?

**science**

How do you calculate the atomic mass of magnesium? 79% magnesium-24, 10% magnesium-25, 11% magnesium-26

**algebra**

Tammy bought 16 cookies for a party. She had 6 cookies decorated at an extra cost of 25 cents each. If the total cost of the cookies was $9.50, how much did each plain cookie cost?

**Science**

What is the initial temperature? If it is just for phase change then the formula is Q = m L Q = 0.063 x 32.3

**Science**

Calculate the amount of heat required to completely sublime 63.0 g of solid dry ice CO2 at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 C.

**Science**

Calculate the amount of heat required to completely sublime 63.0 g of solid dry ice CO2 at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 C.

**Chemistry**

What is the change in internal energy of a system that releases 1275 J of heat to the surroundings and is compressed so that 235 J of work are done on the system?

**english**

thankyou so much that is so helpful

**english**

Im not sure on how to do my introduction on an essay for a school magazine giving your views on how people treat animals? can someone please help me thanks alot

**Geography/History**

sorry i was saying katilin

**ENG**

Choose the correct verb: Some people (know, Knows) more about their favorite TV characters than they do about the members of their own family. A) knows B) know

**chemistry**

A 6.0 L flask contains a mixture of methane, argon and helium at 45 degrees C and 1.75 am. If the mole fractions of helium and argon are 0.25 and 0.35, respectively, how many molecules of methane are present?

**Math**

The number of calls received by a car towing service averages 14.4 per day (per 24 hour period). After finding the mean number of calls per hour, find the probability that in a randomly selected hour the number of calls is 0

**calculus**

let f(x)=sqrt x+4. Calculate the difference quotient f(5+h)-f(5)/h for h=.1 h=.01 h=-.01 h=-.1

**PRE-ALGEBRA**

2V/5+V/4

**Calculus**

A retangular poster is to be made out of cardboard. The margins on the top and the bottom will be 2 inches. The margins on the sides will be 1 inch. The area of the poster devoted to the printed material must be 300 square inches. (a) to the nearest .001 inches, find the ...

**algebra1**

how do you slove x+3y=-30 9x-12y=3 with substitution and elimation

**5th grade math**

How many possible combinations for an 8-digit binary number are there? How did you get this an answer?

**Chemistry**

A square of aluminum foil measuring 3.20 inches on each side weighs 275 mg. The density of aluminum is 2.70 g/cm3. Find the thickness (in micrometers) of the foil.

**algebra 2**

find the average rate of change for the function f(x)=60x-3x^2 between x=6 and x=19

**science 4th grade**

Science fair projets with fish

**english**

where did the jim crow laws take place? and why?

**Calculus**

The shape is a cone. The radius is 6 cm and the height is 9 cm

**Calculus**

If water is poured into a cup at a rate of 1 cubic centimeter per second, how fast is the dept of the water increasing when the water is 4 cm deep? r = 6 cm h = 9 cm V = 1/3(pie) r^2 x h V = (pie)r'h + 1/3 (pie)r^2 h' 6 / 9 = r / h 6h = 9r r = 3 / 4.5 h V = 1/3(pie) (3...

**Calculus**

Okay, I see what I did wrong. I did dy/dt = 6 instead of dy/dt = .5. Thanks a lot

**Calculus**

A street light is hung 18 ft. above street level. A 6-foot tall man standing directly under the light walks away at a rate of 3 ft/sec. How fast is the tip of the man's shadow moving? I know I would've to set up a proportion. 18 / 6 = x + y / y x = distance of man from...

**Calculus**

Two trucks start from the same point. One truck travels due east at a rate of 50 mph and the other trucks travels due north at a rate of 60 mph. At what rate is the distance between the two vehicles increasing 1 1/2 hours later? I think the answer is 55 mph because I added 60...

**Calculus**

The slope is actually -5. And forget I think i understand this now.

**Calculus**

In the diagram below, the y-coordinate of point P is increasing at a rate of 4 units per minute while point Q remains in its fixed position. Find the rate of change of angle, in radians per minute, when y = 20. y ^ | P (0, y) | | | | |---| |___|________ Q (4, 0) Then, P (0 , ...

**calculus**

Your welcome. Don't worry you'll do good in your studies, keep it up

**calculus**

For example, √x is the same as x^1/2, the derivative of √x is 1/2^ -1/2 equals to 1 / 2√x sqrt(3x) = sqrt(3)sqrt(x) and the derivative of this is sqrt(3)*derivative(sqrt(x)) = sqrt(3)/2sqrt(x), as d/dx (sqrt(x)) = 1/2sqrt(x). now, multiply the top and bottom ...

**Managerial Accounting**

A food division reported cost of sales-food of $198,680. Employees' meals cost $1,225, complimentary meals $142 and transfers in were received from the bar operaton with a cost of &82. Determine the net cost of sales.

**alg and trig**

6x^3-5x^2+15x+5 / 2x^2-x+3

**science**

how do u learn the skeleton bones in one night

**NOUNS, PRONOUNS, AND ADJECTIVES**

is a noun to go with it

**Chemistry**

Calcium carbonate reacts with phosphoric acid to produce calcium phosphate, carbon dioxide, and water. 3 CaCO3(s) + 2 H3PO4(aq) Ca3(PO4)2(aq) + 3 CO2(g) + 3 H2O(l) How many grams of phosphoric acid react with excess calcium carbonate to produce 3.47 g Ca3(PO4)2?

**Chemistry**

I did follow those steps and they didn't work for the first problem.

**Math**

i don't know what you mean by infinity?? thanks for the other help (:

**Math**

btw, i don't know if i should switch the sign (greater than or less than) or if it should be negative! thank you

**Math**

i have no idea!!!!!

**Math**

-1/4k is greater than 18

**math in topics**

Wait time for a counselor is 60 minutes. There are five counselors and each counselor see a student for an average of 30 minutes per day. How many new counselors are needed to shorten the wait time to 15 minutes? Each counselor see 5 students per day totaling 25 students

**math in topics**

Wait time for a counselor is 60 minutes. There are five counselors and each counselor see a student for an average of 30 minutes per day. How many new counselors are needed to shorten the wait time to 15 minutes?

**alg2**

Solve: 3x − 7 (sqrt x) + 2 = 0

**alg 2**

simplify (x^3/4)^3

**Social Studies**

for class, my teacher is making us do a booklet of key terms that we need to know. We have to draw pictures for each key term. I need some ideas on what to draw for Articles of Confederation and Land Ordinance of 1785. please help!

**Physics**

a) 4% b) 0.4% c) 0.07%

**HISTORY**

(This homework question was removed due to a copyright claim submitted by K12 Inc.) You do NOT have to write me my paragraph, but what I would like is for you to answer each question next to a bullet-point so I can write my paragraph. For example, answer each of these ...

**math**

2x-3y=12 x=4y+1 substitution, elemenation

**8th grade Math**

I need help finding heighth of a pyramid.

**MT**

Identify 2-3 business issues and provide an explanation of why technology cannot be used to aid or solve them.

**algebra**

thank you.

**algebra**

if a student has an average of 8 after 20 tests and then gets a 0 on his 21st test, what would his new average be?

**Chemistry**

If you start with ten grams of lithium hydroxide, how many grams of lithium bromide will be produced? Round to the nearest tenth. Don't forget the units.

**social studies**

This helped me a lot thank you so much!

**Math**

What is the units you measure for area please help fast

**English**

It's Relative Pronoun. David I is wrong because Demonstrative Pronouns are this, these, that and those.

**physics**

nina has a mass of 40 kg and bruno has a mass of 100 kg. they stand on a slippery surface and push off eachother. bruno has an acceleration of 1.0 m/s squared. what is nina's acceleration?

**PHYSICS**

santa drops a package from his sleigh while traveling at constant velocity. if there is no air resistance, with the package hit the ground in front of the sleigh, behind the sleigh, or directly below it? explain reasoning.

**PHYSICS**

does the sun exert a gravitational force on the earth? if so, why doesn't the earth fall into the sun?

**PHYSICS**

assume you have a mass of 100 kg on earth. on the moon, where the gravitation of the moon is 1/6 gravitation of the earth, what is your mass on the moon and what is your weight on the moon

**PHYSICS**

what are the components of a vector that has a magnitude of 1.5 m at the angle of 35 degrees with respect to the positive x axis

**PHYSICS**

Alex is doing tight circles with his car in an empty parking lot, all the while holding his speedometer reading to a steady 20 mph. Is Alex traveling at a constant velocity? Why or why not?