Wednesday

March 1, 2017
Total # Posts: 148

**probability and Stats**

How can I find standard error from each of the following: a) a proportion & a sample size? b) mean, standard deviation, and sample size? c) mean & standard deviation? thank you

*October 31, 2016*

**Probability and Stats**

A student was totally unprepared for a multiple-choice test and had to absolutely guess the answer to every one of the 100 questions. About what score (percent) would you expect him to earn if there were four possible answers to every question? I'm not sure where to start ...

*October 25, 2016*

**Physics**

what must be the net force if a 19.9 kg mass accelerates to the left at a rate of 2.2m/s^2?

*September 8, 2016*

**Math**

to the nearest hundred, what is the greatest whole number that rounds to 2,500? the least whole number?

*August 22, 2016*

**english**

What do adverbs modify?

*March 9, 2016*

**Physics Grade12**

two balls are juggled so that each ball is in the air for 1.800s, and the second ball is thrown up at the instant the first starts down. Find the height above the throwing hand where the two balls pass eachother, assuming gEarth=9.800m/s^2 I started with d=vt but we don't ...

*February 25, 2016*

**Chemistry**

I wrote the balanced equation for cream of tartar and baking soda: NaHCO3+KHC4H4O6->KNaC4H4)6+H2CO3 I identified the conjugate acid base pairs: NaHCO3 and H2CO3, KHC4H4O6 and KNaC4H4O6 I wrote a balanced equation for carbon dioxide gas and water: H2CO3->H2O+CO2 I ...

*November 30, 2015*

**Physics Electric Circuits**

3. A 15.0 ohm resistor is connected in series to a 120 V generator and two 10.0 ohm resistors that are connected in parallel to each other. b) What is the current through the 15.0 ohm resistor? c) What is the current through one of the 10.0 ohm resistors? b- I did 120 V/15.0 ...

*May 7, 2015*

**Chemistry-Acids**

Thanks. How do I know if a substance is formic acid?

*May 3, 2015*

**Chemistry-Acids**

Write a balanced chemical equation to show the reaction that occurs when each weak acid reacts with water. (Omit states-of-matter from your answer. Use the lowest possible whole number coefficients.) (b) HCHO2 I've gotten a and c correct, and from that I know that ...

*May 3, 2015*

**geometry**

I had to complete the following solution by filling in the missing statements and reasons. I filled out the statements, but am having trouble wording the last two reasons. Following solution: x-2(3x-4)=18 Statement: x-2(3x-4)=18 Reason: Given Statement: x-6x+8=18 Reason: ...

*April 18, 2015*

**educational technology**

Number 4 for further reference is A

*March 12, 2015*

**educational technology**

Its A

*March 12, 2015*

**science**

what is a vector?their structure?

*March 11, 2015*

**History**

Because I'm getting timed

*February 18, 2015*

**History**

1) Which best describes the difference that divide Maayan and Muhammad? A. Age and interest B. physical barriers C. Culture and politics *** D. Economic status 2) How does Maayan most directly experience the conflict in Israel? A. Through treating victims of terrorist attacks...

*February 18, 2015*

**math**

a sample consists of the following n =6 scores: 2, 7, 4, 6, 4, and 7 compute the mean and standard deviation for the sample

*February 16, 2015*

**english**

During the storm, Jenna hid in her basement

*February 2, 2015*

**maths lit,business studies,life science economics**

Yes

*January 20, 2015*

**Chemistry**

What is the empirical formula of a molecule containing 65.5% carbon, 5.5% hydrogen, and 29.0% oxygen? -I found this to be C3H3O and WebAssign says it's right. I need help with part b. If the molar mass of the above compound is 110 grams/mole, what is the molecular formula?

*January 11, 2015*

**math**

Samantha was playing a fraction game where she could earn either positive or negative points on each turn.The lowest score she ever recorded was -26 2/3. The highest score was 8 3/4. Which. What expession represents the distance on a number line between her highest and lowest ...

*December 16, 2014*

**Differential equations in Calculus...plsssss help?**

Sorry for the confusion, it's (-1/15)T+5. And the last part is 75+30e^(-t/15) the fraction is all part of the e and is not divided by each other. I am confused on a through e mainly and g at the end. Should I solve the equation and just plug in 105 and graph the function ...

*November 30, 2014*

**Differential equations in Calculus...plsssss help?**

Suppose that represents the temperature of a cup of coffee set out in a room, where T is expressed in degrees Fahrenheit and t in minutes. A physical principle known as Newton’s Law of Cooling tells us that dT/dt = -1/15T+5 15T + 5. a) Supposes that T(0) = 105. What does ...

*November 30, 2014*

**Calculus with Diffrential Equations: Pleease help?**

Suppose that represents the temperature of a cup of coffee set out in a room, where T is expressed in degrees Fahrenheit and t in minutes. A physical principle known as Newton’s Law of Cooling tells us that dT/dt = -1/15T+5 15T + 5. a) Supposes that T(0) = 105. What does ...

*November 30, 2014*

**Calculus**

Suppose that represents the temperature of a cup of coffee set out in a room, where T is expressed in degrees Fahrenheit and t in minutes. A physical principle known as Newton’s Law of Cooling tells us that dT/dt = -1/15T+5 15T + 5. a) Supposes that T(0) = 105. What does ...

*November 30, 2014*

**Chemistry (Titrations)**

You have to use the M1V1=M2V2 equation for this problem and plug in the values into the appropriate parts of the equation and solve for the missing molar concentration.

*November 30, 2014*

**Help with differential eqs problem???? (Calculus)**

I actually got 36 for K. Is this right? =4sin(3t) h'= 4*3*cos(3t) = 12cos(3t) h"= 12*3*(-sin(3t)) = -36sin(3t) h"= -k*h = -36*sin(3t) =36

*November 30, 2014*

**arithmetic**

In Jullian's garden, there are 3 rows of carrots, 2 rows of string beans,and 1 row of peas. There are 8 plants in each row. How many plants are there in all?

*November 19, 2014*

**science help!!!!!!!!!**

The answer is photosynthesis i just completed the test

*November 7, 2014*

**Chemistry**

A chemical formula shows the types and __blank__ of atoms in the smallest representative unit of a substance.

*October 30, 2014*

**Statistics**

According to a national poll conducted in 2010, seventy percent of teens reported having sent or received a text message while driving. Assume that I randomly survey 14 teens and asked them whether or not they have sent or received a text message while driving. a) What is the ...

*October 27, 2014*

**statistics**

population has mean 53 and standard deviation 12. Calculate the standard deviation of x bar for a random sample of size 12.

*August 18, 2014*

**Math**

Thank you so much.

*May 6, 2014*

**Math**

If two dice are rolled, what is the probability that a total is showing more than four

*May 6, 2014*

**Math**

If two fair dice are rolled, what is the probability that a total of five shows?

*May 6, 2014*

**Math**

Thanks

*May 6, 2014*

**Math**

If two fair dice are rolled, what is the probability that a total of five shows?

*May 6, 2014*

**Math**

Thanks. I got it. The answer is 3,628,800

*May 6, 2014*

**Math**

Suppose that we wish to seat ten people, 5 men and 5 women, in a row of ten chairs. In how many ways can we seat the people with no restrictions?

*May 6, 2014*

**life science,maths lit,geography,tourism**

is it possible 4 me 2bcum a social worker?

*April 30, 2014*

**Public Speaking**

in the speech preparations

*April 14, 2014*

**math**

1. 17x^2+6x-6 2. 3x^3+9x^2+18x did you get the same?

*April 13, 2014*

**math**

If A=3x+4 and B=x^2+2 and C=x^2+3x-2, find the following: 1. AC+B 2. (A+B)(B-C) 3. ABC

*April 13, 2014*

**Chemistry**

The cell diagram for the lead-acid cell that is used in automobile and truck batteries is Pb(s) l PbSO4 (s) l H2SO4 (aq) l PbO2(s), PbSO4(s) l Pb (s) where the comma between PbO2 (s) and PbSO4 (s) denotes a heterogeneous mixture of the two solids and the right-hand lead ...

*February 23, 2014*

**chemistry**

My teacher went over it really fast and now I'm just really confused about how to do my homework =( Calculate the cell potential for the following reaction as written at 25C, given that [Cr2+] = 0.821 M and [Ni2+] = 0.0190 M. Cr(s) + Ni2+ (aq) <==>Cr2+ (aq) + Ni(s) ...

*February 23, 2014*

**Chemistry**

Never mind, it's -.744V I figured it out!

*February 23, 2014*

**Chemistry**

Given these standard reduction potentials at 25 C 1. Cr3+ + e- ===> Cr2+ E1=-0.407 V 2. Cr2+ + 2e- ===> Cr(s) E2=-0.913 V determine the standard reduction potential at 25C for the half-reaction equation Cr3+ + 3e- ===> Cr(s) E=? When I tried, I got 1.08V and I honesty...

*February 23, 2014*

**Art**

Eugene Delacroix's Liberty leading the people commemorated?

*January 31, 2014*

**math**

5 ----- 8+root7 please help me simplify

*December 23, 2013*

**algebra**

thank you.

*December 23, 2013*

**Math**

Determine the equation of g(x) that results from translating the function f(x) = (x + 10)^2 to the right 12 units.

*December 16, 2013*

**Math**

Determine the equation of g(x) that results from translating the function f(x) = x2 + 5 upward 6 units.

*December 16, 2013*

**Math**

Determine the equation of g(x) that results from translating the function f(x) = x2 + 5 upward 6 units.

*December 16, 2013*

**math**

Find the slope of the lines that are (a) parallel lines (b) perpendicular lines to the lines passing through the pair of points (3, 4)(2,-1)

*November 4, 2013*

**math**

Slope is 5 Parallel is 5 or 1/5 Perpendicular is -5

*November 4, 2013*

**math**

Find the slope of the lines that are (a) parallel lines (b) perpendicular lines to the lines passing through the pair of points (3, 4)(2,-1)

*November 4, 2013*

**math**

Write equation in Standard Form Ax + By =C (-9, 7)(0, 3)

*November 4, 2013*

**math**

Thanks

*November 4, 2013*

**math**

Write an equation of the line with the given slope and containing given points. Slope intercept form Slope 4 through (-3, 3)

*November 4, 2013*

**Ed-tech/History question~!**

Yes d is correct i just took the test

*October 28, 2013*

**math**

1.graph equation y=4/5x 2.graph linear equation y=-1 3.find the slope of line -2x - 3y = 5 a. slope is b. slope is undefined?

*October 15, 2013*

**dma040**

Police officer to Speedzilla he was speeding at or above 120 miles per hour. Write an inequality to express Speedzilla speed, then show in graph, write in set notation.

*October 7, 2013*

**dma040**

Solve for x. 13/14x + 8/7 = 6/7x

*October 7, 2013*

**dma040**

Explain which terms are alike 7xy -9x^2 -15xy^2 -14xy

*October 7, 2013*

**Chemistry**

Hi, This is a challenge question for my intro chemistry class and I'd really like to do it. Its in 2 parts. 1. Consider a 2790-lb automobile clocked by law-enforcement radar at a speed of 85.5 mph (miles/hour). If the position of the car is known to within 5.0 feet at the ...

*October 1, 2013*

**Dma 040**

v =1/3ah, solve for h

*September 30, 2013*

**Dma 040**

V=1/3ah, V=21,h=3, solve

*September 28, 2013*

**Dma 040**

Thanx Jai...

*September 27, 2013*

**Dma 040**

V=1/3ah, V=21,h=3, solve

*September 27, 2013*

**Dma 040**

V=1/3ah, V=21,h=3, solve

*September 27, 2013*

**Dma 040**

Lenth of a rectangle is 7ft longer than twice the width. If the rooms perimeter is 158ft, whay are the rooms dimensions? Width Length

*September 27, 2013*

**dma040**

v=1/3ah solve for h

*September 27, 2013*

**dma040**

A number subtracted from 13 is the quotient of -34and 2. Find the number

*September 27, 2013*

**Chemistry**

Please help me out! Gas law homework! How many liters of HCl (g) at STP can be produced from 5.44 g of Cl2 and excess H2 according to the following equation? H2 (g) + Cl2 (g) --> 2 HCl (g) Thank you so much in advance.

*May 28, 2013*

**Chemu**

Hi! I need help with my Chem homework. "When acetylene, C2H2, burns, how many liters of O2 at STp are used for every mole of acetylene burned?" (Balanced equation: 2 C2H2 + 5 O2 --> 4 CO2 + 2 H2O)

*May 28, 2013*

**Biology**

Meh, it's not really hard if you have average memory strength and good note-taking skills. It also depends on how easy-going and clear your teacher is.

*April 29, 2013*

**physics**

what is the magnitude of the resultant of a 6.0n force acting vertically upward and a 4.0n force acting horizontally

*January 1, 2013*

**ap chemistry**

Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction: 2CO2 + O2 yields 2CO2 Delta H for this reaction is -566 kJ/mol run. What is the delta H for CO? 1). +270 kJ/mol 2). -110 kJ/mol 3). +65 kJ/mol 4). -405 kJ/mol 5). -65 kJ/mol 6). -182 kJ/mol 7...

*October 18, 2012*

**ap chemistry ! i am so lost**

how much work is done by the system when 2.00 moles of O2 expand from a volume of 3.00 liters to a volume of 5.8 liters against a constant external pressure of 0.0100 atm? answer in units of J

*October 18, 2012*

**ap chemistry ! i am so lost**

how much work is done by the system when 2.00 moles of O2 expand from a volume of 3.00 liters to a volume of 5.8 liters against a constant external pressure of 0.0100 atm? answer in units of J

*October 18, 2012*

**math**

suppose that you roll a pair of 8-sided dice total of 51 times. what is the probability that you will get a sum of 5 at least 3 times

*September 6, 2012*

**algerabra 1**

how do you find the equation for the line containg the side opposite the side containg the first two vertices?

*June 28, 2012*

**algerabra 1**

how do you find the equation for the line containg the side opposite the side containg the first two vertices?

*June 28, 2012*

**English**

2. If you ask me, there's no hobby like fishing.

*May 2, 2012*

**English**

In which sentence is an a homonym used correctly? 1. Karen's new dog had flees. 2. If you ask me , there's no hobby like fishing. 3. How many ours do we have to wait. 4. We had chocolate ice cream for desert.

*May 2, 2012*

**MATH##$$&&^^****

A researcher wishes to estimate the proportion of college students who cheat on exams. A poll of 490 college students showed that 33% of them had, or intended to, cheat on examinations. Find the margin of error for the 95% confidence interval.

*April 20, 2012*

**MATH**

A mean score on a standardized test is 50 with a standard deviation of 10. Answer the following a. What scores fall between –1 and +1 standard deviation? b. What percent of all scores fall between –1 and +1 standard deviation? c. What score falls at +2 standard ...

*April 3, 2012*

**math**

If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours?

*April 2, 2012*

**Math**

Suppose there are 400 students in your school class. What class rank is the 20th percentile?

*March 28, 2012*

**geometry**

Need to find the perimeter in feet... The width is 35ft and 5in The length is 10ft and 3in Need to write the answer in feet... If there is anybody that can point me in the right direction.. I know I have to convert in. into feet.. and 12in= 1 foot

*December 7, 2011*

**geometry**

Ms. Sue, I am not an expert but I know that the numbers all have to be on one side and the letter on the other Ex. 43+114+X=180 114+43=157 157+X=180 Do the opposite operation to get letter alone so it would be -157 on both sides.. 157+X=180 -157+X=180-157 X=23 Hope that helps

*December 7, 2011*

**business**

A women has $500,000 invested in two rental properties. One yields an annual return of 14% on her investment, and the other returns 9% per year on her investment. Her total annual return from the two investments is $52,000. How much is invested at each return?

*September 20, 2011*

**Geography**

Are there 7 countries in Central America?

*September 19, 2011*

**cognitive and langauge del.**

interactionist

*August 11, 2011*

**Chem 112**

Calculate the pH of a buffer solution prepared by dissolving 0.12 mole of cyanic acid, HCNO and 0.65 mole of sodium cyanate, NaCNO in enough water to make 1.0 liter of solution. [Ka(HCNO) = 2.0 × 10-4] I know that this question has something to do with turning moles into...

*March 21, 2011*

**chemistry**

15ml of 0.325M NaOH is delivered into 35ml HOBr solution of unknown concentration.The pH of the final solution is 7.48. Ka for HOBr is 2.0 x 10-9at 25C. Find the number of moles of OBr- and HOBr in the final solution.

*February 24, 2011*

**math**

how can i find the GCF of a pair of numbers ? (ie 11 18, 8 6)

*January 3, 2011*

**4th grade**

jmk

*November 30, 2010*