# Dr. Jane

Newest questions and responses by Dr. Jane-
## Algebra

i used my brain like u should

*posted on March 22, 2013* -
## stats

You are looking for reduced speeding. I am assuming "md" indicates the mean of the difference. Ho is correct by H1 should be md

*posted on March 14, 2013* -
## Statistics

You have to find the z-score for both 50 and 70 minutes. Change the 1.02 hours to 61.2 minutes for the mean. z = (50 -61.2)/9 do the same for the 70 minutes. go to a standard z-table and find the area between those two values. Do the same thing for B. Your

*posted on March 14, 2013* -
## math

for the second one you have b^2 under a radical sign with an index of 3 (or root of 3) You have some typos in the first one.. but if I am a reading it correctly. (w+9)^3 = -56 take the cube root of both sides w + 9 = cube root of (-56) subtract 9.. the 9

*posted on March 14, 2013* -
## algebra

John's distance = 10t Fred's distance = 12t John + Fred distance = 55 so 55 = 10t + 12 t You can find time in hours by solving the equation.

*posted on March 14, 2013* -
## Math

Use the formula that I gave you in the previous post.

*posted on March 14, 2013* -
## Math

Area of a Triangle = 1/2 x b x h If your units are the same then just enter them into the formula.

*posted on March 14, 2013* -
## Math

(90, 220) and (76, 178) You have two points, so you can write an equation of a straight line in the form or y = mx + b First find the slope: m =(220-178)/(90-76) Once you have the slope. Use it and one of the points to find the equation of the line. To

*posted on March 14, 2013* -
## quick math

12 x 14 =168 square feet. If the pavers were 1 foot by 1 foot we would need 168 pavers BUT.. your paver is 8 inches which is 8/12 or 2/3 of a foot. It is 2/3 times 2/3 or 4/9 square ft 168 divided by 4/9 which is the same as 168 times 9/4 That will get you

*posted on March 14, 2013* -
## math

See the one I just did. Here, you will have to change 960 m to mm 1000 mm = 1 meter

*posted on March 14, 2013* -
## math

First change cm to mm 350 cm = 3500 mm Area = L x W 3500mm = L(50mm) Divide to solve for L

*posted on March 14, 2013* -
## math 7

There are 24 marbles 16 are either green or red 16/24 reduce to get the probability.

*posted on March 14, 2013* -
## statstics

Check the links below. I answered this one last night.

*posted on March 14, 2013* -
## math help please ASAP

This isn't math... probably the science people won't look at it. This looks like biology to me.

*posted on March 13, 2013* -
## Math, Fraction

1/6 times 30 = 5 pennies 1/5 times 30 = _____ nickels 1/3 times 30 = _______dimes Add up your coins and subtract from 30 to find the number of quarters.

*posted on March 13, 2013* -
## math

You are welcome.

*posted on March 13, 2013* -
## math

I did this a minute ago.

*posted on March 13, 2013* -
## pre algebra

Is this (x - 7) divided by (7x - 9)?

*posted on March 13, 2013* -
## Math (algerba 1)

Law of exponents says that you can distibute your power to when multiplying so you would have- 4^2 x 10^-10 I multiplied the two powers.. 4^*1*2) x 10^(-5*2) 16 x 10^-10 I don't know if your teacher wants you to write this in a different form or not. If

*posted on March 13, 2013* -
## math

You can change both fractions to 20ths and then compare the fractions. 4/5 multiply by 4/4 2/4 multiply by 5/5

*posted on March 13, 2013* -
## math

Perimeter = L + L + W + W or P = 2L + 2W L = 5+ 2w P = 2(5+2W) + 2W I replaces the L in the original formula with the 5 + 2w because that equals L according to the problem. 34 = 10 + 4W + 2W Just solve for W. And then you can find L.

*posted on March 13, 2013* -
## math

Which fraction is larger? Since the denominators are the same, just compare the numerators.

*posted on March 13, 2013* -
## Inequalities

-4x >8 excuse my typo x < -2 Lets pretend this is an equation for one minute (x-3)/(x+1) = 5 Put in the -2 (-2-3/(-2-1) =5 -5/-1 =5 We are correct there... so.. Since we have an inequality, we have two choices for the final answer. x> -2 or x > -2 If we

*posted on March 13, 2013* -
## math

1. you have to add 4 to each part of the inequality and then divide by -4. That will cause the same reversal as above. Be careful with that final answer. 2. Multiply each part by -1 25>x>10 You have to turn this around for your final answer.. Like we did

*posted on March 13, 2013* -
## Physics 11

You are welcome.

*posted on March 13, 2013* -
## math

3/12 Reduce this fraction to lowest terms.

*posted on March 13, 2013* -
## maths

Here are a couple examples for you 567,000 in scientific notation is 5.67 x10^5 You always have one number in fron to the decimal place (in the ones place) multiplied 10. If you need to make the number larger the exponet on the 10 is positive. If you need

*posted on March 13, 2013* -
## Math

For the ribbon problem 98 - 12(5) = length of ribbon.

*posted on March 13, 2013* -
## Math

Sam ate 1/4 of 8 is 1/4 x 8 = 2 slices There are 6 slices left.

*posted on March 13, 2013* -
## Math

This should be 3/4 of 12 or 3/4 times 12 = 9 sections

*posted on March 13, 2013* -
## math

19/38 reduce to lowest terms as a fraction or express as a decimal

*posted on March 13, 2013* -
## Statistics

90% confidence interval indicates that 90% of the confidence intervals that you form using the same procedure will contain the true mean of the population. You had a sample and you are trying to predict the mean response from the total population. That is

*posted on March 13, 2013* -
## Physics 11

The second man is travelling for 2 seconds. The first man is travelling for 3 seconds. acceleration due to gravity = 9.8m/sec^2 d = vt v = at we can combine to get d =at^2 a in this case is g. You can find the distance of each jumper and find the

*posted on March 13, 2013* -
## Domain- Interval Notation

You are welcome!

*posted on March 13, 2013* -
## science

D is not right. Electrons move all the time around the nucleus. The travels are not in the nucleus, but they travel around. There are different theories one is that they are in orbitals like the planets around the earth. Really there is cloud of electrons

*posted on March 13, 2013* -
## math

For the first one just add 7 to each part of the inequality. that will leave x alone in the middle. For the second one, this gets a little tricky. You have to divide each part of the inequality by -12. Whenever you multiply or divide and inequality by a

*posted on March 13, 2013* -
## math

You have to look for a pattern. I would put them in order input 8 ___ 16 22 30 50 output___ 10 11 14 18 28

*posted on March 13, 2013* -
## Stats help

There is data for these 5 people before and after the class. You have two sets of data and since it is the same people in both groups this is a dependent test.

*posted on March 13, 2013* -
## math

You cannot simplify if you have a sum of x + y under a square root. if you have xy under a square root, you can write it as square root of x times the square root of y.

*posted on March 13, 2013* -
## math

I hope your other one didn't need matrices because..I did it the other way. 4 -1 -3 8 2 2 -1 3 6 1 -3 2 You want to manipulate the rows so that in the end, you end up with 1 0 0 a where a = the value for x 0 1 0 b where b = the value for y 0 0 1 c where c

*posted on March 13, 2013* -
## math

Your goal is to go from 3 equations in 3 variables down to 2 equations in 2 variables. It is up to you to decide which variable you want to eliminate. I think I might try eliminating the y. Add the first two equations together. since the y's are equal and

*posted on March 13, 2013* -
## Domain- Interval Notation

Under the overall square root you have 3 - square root of 25-x^2 What is under the radical sign has to be positive. Domain is the X values that will result in a solution and not undefined. It looks like you can have x=-5 and x =5 because that will give a

*posted on March 13, 2013* -
## Inequalities

Multiply both sides times x + 1 x-3 > 5x + 5 -4x > 2 x 5 -8/-4 >5 2 > 5 That is correct 2 is greater than 5.

*posted on March 13, 2013* -
## statstics

z = (x - 32)/1.2 For 1: you have to use a z-table to find the value where 99% of the values are less than that number meaning that there is 1% in the upper tail. Z-tables to differ from book to book, be sure to read it carefully. Once you have that z-

*posted on March 13, 2013* -
## Math

Another approach is to use: y = mx + b You will have m, x and y. solve for b. Write an equation where you have a value for m and b. You can then figure out another x and y that will work in that equation.

*posted on March 13, 2013* -
## Math

I have to see the line shown. We need the slope of the line shown. Grant's line will have a slope that is a negative reciprocal of the line shown. for example if the line has a slope of -3, Grant's perpendicular line will be 1/3. To find the other point,

*posted on March 13, 2013* -
## maths

You can do this the same way that you would factor x^2 - x - 90 But.. this time we have x^4 and x^2 (x^2 -10)(x^2 +9)

*posted on March 13, 2013* -
## Math: Please check

48 is 16 x 3 Take the square root of 16 =4 4 square root of 3 Now look at n^9 that can be written as n times n^8 n^4 comes out and leaves n under the square root sign. your answer should be 4n^4 square root of (3n) One way to get an better understanding of

*posted on March 13, 2013* -
## Math

36/390 Probability can be represented as a reduced fraction or as a decimal

*posted on March 13, 2013* -
## Math: Please help

To find the square root of 140 I started with 14 times 10 then 7 times 2 times 2 times 5 I have a perfect square of 4 and take the square root which puts the 2 out in front of the square root. 2 times the square root of (35)

*posted on March 13, 2013* -
## Geometry

Can you prove it by side angle side? AB = BC BD = BD it is a shared side Angle ABD = Angle CBD We have 2 sides and the angle between those 2 sides. I drew a picture.

*posted on March 13, 2013* -
## Math

You are right.. it could also be 36

*posted on March 13, 2013* -
## math

You distribute the power to each part. 14^4y^4 Most teachers would let you leave the answer like this. They wouldn't want you to work out 14^4. Maybe your teacher does. If so.. 14*14*14*14

*posted on March 13, 2013* -
## algebra

1/2 - 3m/4 + 7 = 4m -9 - m/28 Let's get all of the m's on one side and all of the constants on the other. 1/2 + 7 + 9 =4m - m/28 + 3m/4 1/2 + 14/2+18/2 = 28(4m)/28 - m/28 +21m/28 33/2 = combine the m terms and then solve for m by cross multiplying.

*posted on March 13, 2013* -
## Math

4 + 6+ 8 parts or slices 18 slice/5 people Each person can have 3 slices with 3 slices left over If you want to share the extra 3 slices with 5 people then each person gets another 3/5 of a slice.

*posted on March 12, 2013* -
## Math

Sorry.. I didn't mean to post that. the answer gives us x =1 not 3 and we get to 6 dimes, but your problem is talking about more than 10 dimes. The one pile works because you have 4(1)+ 2 = 5(1) + 1 6 =6 . Now, we have to find a multiple that will work...

*posted on March 12, 2013* -
## Math

You have to work with piles = x 4x + 2 = 5x +1 x = 3 if you substitute you have 14 dimes 3 piles of 4 = 12 plus 2 = 14 3 piles of

*posted on March 12, 2013* -
## Math

You can use a Venn Diagram 12 - 5(0verlap) = 7 football 17 - 5 = 12 Add up 7 + 12 + 5 = subtract from 30

*posted on March 12, 2013* -
## Math

You are looking for numbers between 30 and 50 These numbers must be in the 40s. Which number in the 40s has a 6? Would it be 46?

*posted on March 12, 2013* -
## Math

The equation is balanced. 1 liter of N2/ 3 liters of H2 5 liters of N2/ x liters of H2 Set the two fraction equal and cross multiply to solve for x.

*posted on March 12, 2013* -
## chemistry

There is a carbon in the middle. There is an H on each side of the Carbon plus one above with a Cl on the under the C.. The order doesn't really matter. You just have to show a Carbon with 3 H bonds and 1 Cl bond. Cl H C H H

*posted on March 12, 2013* -
## math

I don't see your exponent. Is it (14y)^4 ?

*posted on March 12, 2013* -
## math

You can either change all of the fractions to decimals or you can get common denomiators. You wil work with smaller numbers if you change 4/6 to 2/3 4/8 to 1/2 Now, you need a common denominator for 2/3 1/2 3/4 5/8 24 would work as your denominator. Once

*posted on March 12, 2013* -
## stats

You have to compare the -2.29 either with the significance level of say .05 You will go to a t-table look up the -2.29 with the correct degrees of freedom and compare that value with the .05. If it is less then you reject, if it is more you fail to reject.

*posted on March 12, 2013* -
## math

How about.. If it is 40% off, then you are paying 60% of the price. .60 (60) = $36.00

*posted on March 12, 2013* -
## stats

It depends on your book It can be set up as Ho: mu1 = mu 2 Ha: mu1 does not equal mu2 or other books write it as: Ho: mu1 - mu2 = 0 Ha: mu1 - mu2 does not = 0

*posted on March 12, 2013* -
## Science

Pressure is he best answer.

*posted on March 12, 2013* -
## math

71/568 were unsatisfied reduce the fraction to 1/8

*posted on March 12, 2013* -
## to Dr Jane

I just found it... I need to stay away from Language Arts... Thanks again.

*posted on March 12, 2013* -
## to Dr Jane

I just saw a posting by Brandi about tacos. Is that the one? My answer is still there and I think it is right. I do appreciate that you removed anything that I did wrong. I certainly don't want to give anyone the wrong answer.

*posted on March 12, 2013* -
## to Dr Jane

Thanks!!!!!

*posted on March 12, 2013* -
## math

You could setup fractions and cross multiply: 1 = 1x so x = 1

*posted on March 12, 2013* -
## to Dr Jane

Where did I make the mistake? I am trying to be careful. Sorry!!! Actually, I just found a mistake that someone else made. They posted a 46 for an answer of addition/subtraction of a polynomial. I can see how annoying this can be. I will be more careful.

*posted on March 12, 2013* -
## Math

2x^4 + 2x -1 add 2x^4 + 2x-1 because these are two legs of the triangle. 4x^4 + 4x -2 Now subtract this from the perimeter to get the length of the base. Actually with signed numbers, we don't subtract, we add the opposite. 5x^4-2x^3 + x - 3 + -4x^4 -4x +2

*posted on March 12, 2013* -
## Science

You are welcome.

*posted on March 12, 2013* -
## physics

Force = mass times acceleration.

*posted on March 12, 2013* -
## math

$1000 + .09(2000)

*posted on March 12, 2013* -
## Math

Unit rates is that you have to express the answer as 1 hour or per hour. 20 mi/ 2 h divide both by 2 and you will get some number of miles/1 hour

*posted on March 12, 2013* -
## stats

Ho: Mu = 150 Ha: Mu >150 some books set up Ho: as Mu is less than or equal to because the go in the opposite direction of the Ha. The Ho always includes the = You are testing to see if your mean is significantly different from the known 150. When you do

*posted on March 12, 2013* -
## stats

You can see that you have two samples here so you will do either an indep or dep. test. We usually use a dependent test if we are using twins or triples, married couples or if we repeat the test with the same students and using a different criteria. That

*posted on March 12, 2013* -
## math

1 inch is about 2.5 cm so 7 inches would = ?

*posted on March 12, 2013* -
## math

Area = length x width Length = width + 6 A = lw l = w + 6 315 = (w+6)(w) 315 = w^2 +6w 0 = w^2 + 6w - 315 0 = (w+21)(w-15) w+21 = 0 w - 15 = 0 w = -21 w = 15 discard the -21 because we don't measure distance in negative numbers. w = 15 l = 21 Multiply to

*posted on March 12, 2013* -
## math

percentage increase (1072 - 841)/841 You will get a decimal. Move the decimal point two places to the right and include the % sign.

*posted on March 12, 2013* -
## maqth

I am thinking: 654 times 4. Multiply the 1 digit number times the ones digit in the number. Write down the ones value and carry the tens. For my example: when multiplying by 4 my first step is 6 carry 1 tens to the tens place multiply the 4 times the tens

*posted on March 12, 2013* -
## math

Six hundred thirty. There should not be an "and" unless there is a decimal point. Hopefully, it is 630 1000 mg = 1 gram So, you have less then a gram 1 gram/1000 mg = ?/ 630

*posted on March 12, 2013* -
## Math

more than is > 840/4 = 210 t>210

*posted on March 12, 2013* -
## fraction

5 3/4 - 3 2/5 Change 3/4 to 15/20 change 2/5 to 8/20 5 - 3 = 2 15/20 -8/20 = 7/20 Ans. 2 7/20

*posted on March 12, 2013* -
## stats

This is a one sample test. It is one sample because you aren't comparing groups, etc.

*posted on March 12, 2013* -
## physics

I am back... if the elevator is free falling, you would have zero gravity. I guess you should be worried.

*posted on March 12, 2013* -
## physics

Not if the elevator is moving.

*posted on March 12, 2013* -
## maths

for a numerical value, use a calculator to find the square root of 2. Multiply that answer by 2 and add 3 Then take the square root of that final answer.

*posted on March 12, 2013* -
## algebra 1

you have to think of two numbers that multiply to equal -48 and add to be -48 I can't think of anything that will work here. -48 = -24 times 2 or -2 times 24 = -48 times 1 or -1 times 48 Do you have a typo?

*posted on March 12, 2013* -
## Math: Probability

dependent in the first one would be choosing a cookie at random and eating it and then choosing another. By eating that first cookie, you changed the probability of getting a second cookie. Indep for the second one would be flipping a coin and rolling a

*posted on March 12, 2013* -
## Chem

nonpolar is when they share electrons equally.

*posted on March 12, 2013* -
## Science

You are correct. distance/ time = speed. Velocity is speed plus direction.

*posted on March 12, 2013* -
## College Mathematics

There are 13 clubs and then 3 jacks. 16/52 Using the rule P(J) = 4/52 P(C) = 13/52 P(C + J) = 1/52 the Jack of Clubs

*posted on March 12, 2013* -
## STAT

1. 6 feet = 72 inches You need to find the z score (number - mean) divided by SD 72 -66/2.5 = z score Then use a standard z-table to find the area of under the curve to the right of that number. This number will be your %. 2. Find the z-score for 67 and

*posted on March 12, 2013* -
## algebra

(5x -3)(5x-3) 25^x^2 -30x +9 I start with the above factors because of the 25 and the 9 and the requirement of one distinct room. So.. a-15 = -30

*posted on March 12, 2013* -
## algebra

You can change 1/4 = a number /100 then you can compare the two fractions. multiply the numerator and the denominator of 1/4 by 25 to get ?/100

*posted on March 12, 2013* -
## venn diagram

You have to subtract the overlap of 210 from 630 and that will just be P and won't include any Q.

*posted on March 12, 2013*