# Posts by Jen

Total # Posts: 3,504

**physics**

a helicopter has a speed relative to the air of 76km/h northeast. The speed of the wind relative to the ground is 28km/h south. 2 hours after leaving the ground, what is the displacement of the helicopter relative to the ground?

*November 11, 2011*

**math**

a) 7.49 miles b) 0.12 miles per minute

*November 10, 2011*

**Biology**

How can you experimentally determine the total volume of blood in a human?

*November 6, 2011*

**Science**

Are you then suggesting that because humans are not predators, their eyes have a more constricted view than owls?

*November 6, 2011*

**Science**

Why are your ears at the side of your head and not in front where your eyes are?

*November 6, 2011*

**chemistry**

sample of argon gas collected at a pressure of 1.11 atm and a temperature of 28.0 oC is found to occupy a volume of 20.3 liters. How many moles of Ar gas are in the sample?

*November 5, 2011*

**Physics**

A rock thrown with an initial velocity of 35 m/s at an angle of 48° with respect to the horizontal has a range of 963 m on a certain planet. What is the acceleration of gravity on this planet?

*November 4, 2011*

**MATH**

Assume that the population of heights of male college students is approximately normally distributed with mean of 72.83 inches and standard deviation of 6.86 inches. A random sample of 93 heights is obtained. Show all work. (A) Find the mean and standard error of the x ...

*November 3, 2011*

**MATH...PLZ HELP**

The width of the Confidence Interval is inversely related to the Maximum Error of Estimate. T or F? Why or why not?

*November 3, 2011*

**MATH....**

Determine the level of the confidence given the confidence coefficient z(α/2) for the following situation: z(α/2) = 1.96

*November 3, 2011*

**MATH**

Given a binomial distribution with n = 21 and p = 0.76, would the normal distribution provide a reasonable approximation? Why or why not?

*November 2, 2011*

**Math**

pattern rule for 2,3, ___, 7, 11, 13, 17, ___

*November 2, 2011*

**physics**

thank you so much!!!

*November 2, 2011*

**physics**

thank you! From here how would I get this: Suppose the torque you found for the last part is being produced by a force applied at a point 0.15·m from the axis. If the direction of the force is perpendicular to a line from the axis to that point, what is the magnitude of...

*November 2, 2011*

**physics**

Consider a 8·kg rod with a length of 0.6·m and rotating about an axis passing through its center. (a) What is its rotational inertia? (B) Suppose the rod is rotating counterclockwise and speeding up with a rotational acceleration of 7·rad/s2. What is the ...

*November 2, 2011*

**math**

Consider a 8·kg rod with a length of 0.6·m and rotating about an axis passing through its center. (a) What is its rotational inertia?

*November 2, 2011*

**math**

Consider a 8·kg rod with a length of 0.6·m and rotating about an axis passing through its center. (a) What is its rotational inertia?

*November 2, 2011*

**Biology**

Can genetic mutations also occur within mitochondria and cause diseases? if yes, how common are these diseases?

*October 31, 2011*

**Chemistry**

Hydrogen sulfide is an impurity in natural gas that must be removed. One common removal method is called the Claus process, which relies on the reaction: 8 H2S(g) + 4 O2(g)--> S(l) + 8 H2O(g) Under optimal conditions the Claus process gives 98% yield of S8 from H2S. If you ...

*October 31, 2011*

**Chemistry**

Which of the following solutions is the most basic? (a) 0.6 M NH3, (b) 0.150 M KOH, (c) 0.100 M Ba(OH)2. Explain.

*October 31, 2011*

**MATH**

A set of 50 data values has a mean of 18 and a variance of 4. I. Find the standard score (z) for a data value = 20. II. Find the probability of a data value < 20.

*October 30, 2011*

**math**

nevermind got it :-)

*October 27, 2011*

**math**

A large truck with a mass of 6500·kg and going 20·m/s east collides with a car whose mass is 1100·kg and which is at rest. If the impulse exerted on the car by the truck is 12000·N·s east, find the impulse exerted by the car on the truck. ...

*October 27, 2011*

**math**

Thank you sooo much!!! I wasn't dividing by the right number! can you also explain how to find the impulse of this problem? A large truck with a mass of 6500·kg and going 20·m/s east collides with a car whose mass is 1100·kg and which is at rest. If ...

*October 27, 2011*

**MATH**

i'm not sure how that site relates to my question at all???

*October 27, 2011*

**MATH**

Find the z-score for the standard normal distribution where: Area = 0.95 to the left of z

*October 27, 2011*

**MATH**

What percentage of the area of the standard normal distribution is between z = -1.00 and z = +1.00? How do you know this?

*October 27, 2011*

**Did i do this right??? STATS**

3. In testing a new drug, researchers found that 10% of all patients using it will have a mild side effect. A random sample of 14 patients using the drug is selected. Find the probability that: (A) exactly two will have this mild side effect (B) at least three will have this ...

*October 26, 2011*

**Math**

In testing a new drug, researchers found that 10% of all patients using it will have a mild side effect. A random sample of 14 patients using the drug is selected. Find the probability that: (A) exactly two will have this mild side effect (B) at least three will have this mild...

*October 26, 2011*

**math**

block A: mass = 100·g, spring stretched 10·cm block B: mass = 400·g, spring stretched 20·cm block C: mass = 200·g, spring stretched 20·cm block D: mass = 200·g, spring stretched 20·cm Rank the blocks, from largest to ...

*October 25, 2011*

**chemistry**

write a balanced equation for photosynthesis. express the answer as a chemical equation. identify all of the phases in the answer. during photosynthesis, plants use energy from sunlight to form glucose (C6H12O6(s)) and oxygen from carbon dioxide and water

*October 25, 2011*

**chemistry**

honestly all we do is labs during class i would love to take notes

*October 25, 2011*

**chemistry**

we dnt take notes that's why im so lost

*October 25, 2011*

**chemistry**

use standard enthalpies of formation to calculate delta Hrxn for the following reaction. 2H2S(g)+3O2(g)-->2H2O(l)+2SO2(g) express the answer using four significant figures Delta Hrxn = ? kJ

*October 25, 2011*

**chemistry**

use standard enthalpies of formation to calculate delta Hrxn for the following reaction. 2H2S(g)+3O2(g)-->2H2O(l)+2SO2(g) express the answer using four significant figures Delta Hrxn = ? kJ

*October 25, 2011*

**Stats....PLZ HELP....**

A bag of colored blocks contains the following assortment of colors: red (18), blue (14), orange (20), purple (14), green (10), and yellow (4). Construct the probability distribution for x.

*October 25, 2011*

**Stats**

Find the mean and standard deviation of the following probability distribution: x 1 2 3 P(x) 0.3 0.5 0.2

*October 25, 2011*

**Stats**

x y 1 -10.0 2 -20.0 3 -30.0 4 -40.0 5 -50.0 - What would be the slope of this regression line? - Would the correlation between x and y be positive or negative? - How would you interpret these data in terms of linear regression?

*October 25, 2011*

**Stats**

In testing a new drug, researchers found that 10% of all patients using it will have a mild side effect. A random sample of 14 patients using the drug is selected. Find the probability that: (A) exactly two will have this mild side effect (B) at least three will have this mild...

*October 25, 2011*

**math**

Consider the experiment of simultaneously tossing a fair coin and rolling a fair die. Let X denote the number of heads showing on the coin and Y the number of spots showing on the die. a. List the outcomes in S. b. Find Fx,y(1,2). Part a is easy. It's part b that I don'...

*October 25, 2011*

**eth**

should united states government policy favor certain kinds of immigrants?

*October 23, 2011*

**statistics**

Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of 32 grams of fat per pound, with a standard deviation of 7.5 grams of fat per pound. A random sample of 34 farm-raised trout is selected. The mean fat content for the ...

*October 23, 2011*

**statistics**

Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of 32 grams of fat per pound, with a standard deviation of 7.5 grams of fat per pound. A random sample of 34 farm-raised trout is selected. The mean fat content for the ...

*October 23, 2011*

**Chemistry**

n=4,n=6

*October 22, 2011*

**Math**

You are given the following data. # of Absences Final Grade 0 96 1 92 2 71 3 66 4 60 5 51 A. Find the correlation coefficient for the data. B. Find the equation for the regression line for the data, and predict the final grade of a student who misses 3.5 days.

*October 21, 2011*

**Math**

Three cards are selected, one at a time from a standard deck of 52 cards. Let x represent the number of tens drawn in a set of 3 cards. (A) If this experiment is completed without replacement, explain why x is not a binomial random variable. (B) If this experiment is completed...

*October 21, 2011*

**Math**

A. If the correlation coefficient is 0.65, what is the sign of the slope of the regression line? B. As the correlation coefficient decreases from -0.97 to -0.99, do the points of the scatter plot move toward the regression line, or away from it?

*October 21, 2011*

**Math**

This is so confusing to me :( what would i do next??

*October 21, 2011*

**Math**

For the table that follows, answer the following questions: x y 1 1/2 2 1 3 3/2 4 - Would the correlation between x and y in the table above be positive or negative? - Find the missing value of y in the table. - How would the values of this table be interpreted in terms of ...

*October 21, 2011*

**Can somehelp me with this ASAP plz?!?!?! Stats**

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 I. What score was earned by more students than any other ...

*October 19, 2011*

**Stats**

In each of the four examples listed below, one of the given variables is independent (x) and one of the given variables is dependent (y). Indicate in each case which variable is independent and which variable is dependent. I. Rainfall; Crop yield II. Taxi fare; Length of ride ...

*October 19, 2011*

**Stats**

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 I. What score was earned by more students than any other ...

*October 19, 2011*

**Stats....how do i do this??**

It doesn't show .16, it shows .15 as p-value of 0.4404 and z as 1.15....what do i do??

*October 18, 2011*

**Stats....how do i do this??**

SAT I scores around the nation tend to have a mean scale score around 500, a standard deviation of about 100 points, and are approximately normally distributed. What SAT I score within the population would have a percentile rank of approximately 16? Im not sure how to do this...

*October 18, 2011*

**Stats...is this correct??**

Scores on the Stanford-Binet Intelligence scale have a mean of 100 and a standard deviation of 16, and are presumed to be normally distributed. A person who scores 68 on this scale has what percentile rank within the population? z = (68-100)/16 z = -32/16 = -2 So would it be ...

*October 18, 2011*

**Stats...is this correct?**

Yay!! Thank u!!

*October 18, 2011*

**Stats...is this correct?**

A sample of purchases at the local convenience store has resulted in the following sample data, where x = the number of items purchased per customer and f = the number of customers. x 1 2 3 4 5 f 5 15 8 8 7 1. What does the 15 stand for in the above table? 2. Find the midrange...

*October 18, 2011*

**Stats**

I. Dependent variable; Independent variable II. Independent variable; Independent variable III. Independent variable; Dependent variable IV. Dependent variable; Dependent variable Sorry I misread it. Is this correct?

*October 18, 2011*

**Stats**

6. In each of the four examples listed below, one of the given variables is independent (x) and one of the given variables is dependent (y). Indicate in each case which variable is independent and which variable is dependent. I. Rainfall; Crop yield II. Taxi fare; Length of ...

*October 18, 2011*

**Stats**

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 I. What score was earned by more students than any other ...

*October 18, 2011*

**CHEMISTRY HELP**

1) The specific heat of solid copper is 0.385 J/g(C). What thermal energy change occurs when the temperature of a 34.10 g sample of copper is cooled from 35.7 degrees Celsius to 13.9 degrees Celsius? Answer: -286.3 J This amount of heat is used to melt solid ice at 0.0 degrees...

*October 17, 2011*

**Statistics**

SAT I scores around the nation tend to have a mean scale score around 500, a standard deviation of about 100 points, and are approximately normally distributed. What SAT I score within the population would have a percentile rank of approximately 16?

*October 17, 2011*

**Statistics**

It says to calculate using this: Nk/100 So im not sure if i did it correctly....

*October 17, 2011*

**Statistics**

z = (68-100)/16 z = -32/16 = -2 So would it be 95%?

*October 17, 2011*

**Statistics**

Scores on the Stanford-Binet Intelligence scale have a mean of 100 and a standard deviation of 16, and are presumed to be normally distributed. A person who scores 68 on this scale has what percentile rank within the population?

*October 17, 2011*

**Statistics**

So the midrange of items purchases would be 3. 5+30+24+32+35 = 126 items were purchased by the customers in this sample. Did i do this correctly?

*October 17, 2011*

**Statistics**

A sample of purchases at the local convenience store has resulted in the following sample data, where x = the number of items purchased per customer and f = the number of customers. x 1 2 3 4 5 f 5 15 8 8 7 •What does the 15 stand for in the above table? •Find the ...

*October 17, 2011*

**Statistics**

I. dependent variable II. independent variable III. independent variable IV. dependent variable Is this correct?

*October 17, 2011*

**Statistics**

In each of the four examples listed below, one of the given variables is independent (x) and one of the given variables is dependent (y). Indicate in each case which variable is independent and which variable is dependent. I. Rainfall; Crop yield II. Taxi fare; Length of ride ...

*October 17, 2011*

**Statistics**

A student scored 81 percent on a test, and was in the 77th percentile. Explain these two numbers.

*October 17, 2011*

**Statistics**

In terms of the mean and standard deviation: -What does it mean to say that a particular value of x has a standard score of +2.1? -What does it mean to say that a particular value of x has a z-score of -2.4?

*October 17, 2011*

**Stats**

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 Answer each of the following: I. What score was earned by ...

*October 17, 2011*

**math**

A 1200·kg elevator is attached to a cable whose tension is 11900·N. What is the magnitude of the elevator's acceleration? ____ m/s

*October 16, 2011*

**chemistry**

what is the typical relationship between the rate of reaction and the value of the equilibrium constant? A) it is a direct porportionality B) it is an exponential proportionality C) it is an inverse proportionality D) there is no relationship between these factors

*October 14, 2011*

**math**

A ball is thrown from the edge of a cliff with an initial velocity of 60·m/s upward. Answer the following questions using + (upward) and - (downward) to indicate the direction of the velocity. Ignore air resistance and assume the ball does not hit the ground during the ...

*October 13, 2011*

**physics**

The hang-time of a basketball player who jumps a vertical distance of 2 feet (0.61 m) is about 0.70 second. What will be the hang-time if the player reaches the same height while jumping 3 feet (0.91 m) horizontally?

*October 13, 2011*

**Stats**

A set of 50 data values has a mean of 15 and a variance of 25. Find the standard score of a data value = 20. I'm not sure how to do this....please help

*October 12, 2011*

**Help plz!! Math....**

Start with x = 100 and add four x values to make a sample of five data such that the standard deviation of these data equals 0

*October 12, 2011*

**Help plz!! Math....**

A set of 50 data values has a mean of 15 and a variance of 25. Find the standard score of a data value = 20

*October 12, 2011*

**Physics**

A 4.3-kg block slides down an inclined plane that makes an angle of 26° with the horizontal. Starting from rest, the block slides a distance of 2.1 m in 5.1 s. Find the coefficient of kinetic friction between the block and plane.

*October 12, 2011*

**sentence**

I show my appreciation to my parents for all they do for me :)

*October 12, 2011*

**4th grade math**

add all of them and divide by how many sets there are which is 5.... 92 + 96 + 99 + 103 + 88 = 478/5 = 95.6

*October 12, 2011*

**Statistics**

Start with x = 100 and add four x values to make a sample of five data such that the standard deviation of these data equals 0

*October 12, 2011*

**Statistics**

A set of 50 data values has a mean of 15 and a variance of 25. Find the standard score of a data value = 20

*October 12, 2011*

**Can someone help me please? MATH**

hmmmmm i guess it is....thank u :)

*October 11, 2011*

**Can someone help me please? MATH**

Identify the sampling technique used to obtain this sample: Each person boarding a plane is asked to flip a coin; those showing “tails” have their luggage searched.

*October 11, 2011*

**Math**

interesting....thank you for your example, it definitely helped me :)

*October 11, 2011*

**Math**

In your own line of work, give one example of a discrete and one example of a continuous random variable, and describe why each is continuous or discrete.

*October 11, 2011*

**Math**

Identify the sampling technique used to obtain this sample: Each person boarding a plane is asked to flip a coin; those showing “tails” have their luggage searched.

*October 11, 2011*

**Chemistry**

I have no idea where to even start with this problem on my pre-lab! For part of the experiment, you will need to prepare 100 mL of 0.025 M CH3CO2H, starting from commercial "glacial" acetic acid, which has a concentration of 17.4 M. This is best done by making two ...

*October 10, 2011*

**Math-Stats**

An insecticide company exposes 10,000 cockroaches to its newest product, and exposes another 10,000 to their previous formula. The researchers use videotape to count how many cockroaches are still alive, and how many appear to be in distress, at 10 second intervals. When the ...

*October 10, 2011*

**Math**

actually i do check and actually that is another problem i posted, not this damn problem!

*October 10, 2011*

**Math**

Construct a grouped frequency distribution for the following 28 scores using a class width of 4: 64 63 58 46 52 62 47 49 56 47 43 41 45 51 60 62 51 61 50 55 56 53 54 58 48 48 58 46 How do I do this?

*October 10, 2011*

**Math**

A candidate for a political office claims that he will win the election. A poll is conducted, and 35 of 150 voters indicate that they will vote for the candidate, 100 voters indicate that they will vote for his opponent, and 15 voters are undecided. a. What is the population ...

*October 10, 2011*

**Chemistry**

Regular-strength chlorine bleach is a 5.25% solution of NaClO. how many milliliters of 0.02005 M sodium thiosulfate will be required to reach the equivalence point in the titration of a 1.000ml sample of Bleach by reacting the ClO- ions with I, then titrating the resulting I2 ...

*October 10, 2011*

**Math...PLEASE HELP!!!!**

A candidate for a political office claims that he will win the election. A poll is conducted, and 35 of 150 voters indicate that they will vote for the candidate, 100 voters indicate that they will vote for his opponent, and 15 voters are undecided. a. What is the population ...

*October 9, 2011*

**Math**

how in the world do i do this??

*October 9, 2011*

**Math**

Construct a grouped frequency distribution for the following 28 scores using a class width of 4: 64 63 58 46 52 62 47 49 56 47 43 41 45 51 60 62 51 61 50 55 56 53 54 58 48 48 58 46

*October 9, 2011*

**Math**

A candidate for a political office claims that he will win the election. A poll is conducted, and 35 of 150 voters indicate that they will vote for the candidate, 100 voters indicate that they will vote for his opponent, and 15 voters are undecided. a. What is the population ...

*October 9, 2011*

**Math-Ms. Sue or Bob**

Can either one of you help me with the math problems I asked? I really need help and do not understand how I would calculate the sample statistic and parameter population....

*October 9, 2011*