Friday

January 20, 2017
Total # Posts: 2,408

**Chemistry**

counts/min time(hours) 800 0 713 1 450 5 200 12 112 17 a. 5h b. 6h c. 12h d. 99h

*December 10, 2011*

**Chemistry**

The table wasn't available

*December 10, 2011*

**Chemistry**

Tc-99 is a radioactive isotope that decays by beta emission and is used by radiologists in the diagnosis of liver disease. Its decay behavior is shown by the activity-time table. What is its half-life?

*December 10, 2011*

**statistics**

The probability any one widget is free of defects is 0.93. For quality control purposes the company is concerned about bad batches of widgets. If the widgets are shipped in batches of 20, find the probability of at most 2 defective widgets in one batch.

*December 9, 2011*

**science**

help me plz

*December 8, 2011*

**Creative Writing**

mainly about a jewish breast cancer organization called sharsheret, which is hebrew for chain, it links young jewish women all over the world to eachother so they can speak about their illness. and i am also focusing on the gene mutation BCRA 1 and 2 that is most commonly ...

*December 5, 2011*

**Creative Writing**

Anyone have any suggestions for a title on an essay about breast cancer?

*December 5, 2011*

**trig**

a 30 foot ladder leans against a wall at a 71 degree angle of elevztion find the distance of a ladder's base to the wall

*December 3, 2011*

**math**

Jane is taking a class and asks you to help her figure out what her last grade must be in the class to get a 85 in the class. She tells you the following calculation is used to find your final grade: 75+85+90+X ___________ > 4 x is her last score which has not been taken. ...

*November 30, 2011*

**math**

Jane is taking a class and asks you to help her figure out what her last grade must be in the class to get a 85 in the class. She tells you the following calculation is used to find your final grade: 75+85+90+X ----------- > or = to 85 4 x is her last score which has not ...

*November 29, 2011*

**algebra**

Jane is taking a class and asks you to help her figure out what her last grade must be in the class to get a 85 in the class. She tells you the following calculation is used to find your final grade: w2d2 x is her last score which has not been taken. Explain this equation and ...

*November 29, 2011*

**math**

Jane is taking a class and asks you to help her figure out what her last grade must be in the class to get a 85 in the class. She tells you the following calculation is used to find your final grade: w2d2 x is her last score which has not been taken. Explain this equation and ...

*November 29, 2011*

**math - Please help me to understand**

The average selling price of homes in a certain city is $356,300. Assume the variable is normally distributed with a standard deviation of $64,600. If 396 homes are for sale, how many homes will sell for more than $325,000? (Round up to the next whole number.) I don't ...

*November 29, 2011*

**math - Please help me to understand**

The average selling price of homes in a certain city is $356,300. Assume the variable is normally distributed with a standard deviation of $64,600. If 396 homes are for sale, how many homes will sell for more than $325,000? (Round up to the next whole number.) I don't ...

*November 28, 2011*

**Intermediate algebra**

Hello, I am kind stuck on this question In the lab you discover a relationship between the temperature of the air and the speed of sound. You find the speed of sound is never lower than 331 m/s and increases by 60% of the current temperature. a. What is the equation from this ...

*November 28, 2011*

**math**

Did I figure this right? score-mean is 356,300/64,600(SD)= 5.515 My book says that any z values beyond 3.25 us a=0.500. so I multiplied 0.500 by 396 = 198 I this correct?

*November 28, 2011*

**math**

The average selling price of homes in a certain city is $356,300. Assume the variable is normally distributed with a standard deviation of $64,600. If 396 homes are for sale, how many homes will sell for more than $325,000? (Round up to the next whole number.)

*November 28, 2011*

**Statistics**

Please someone help me to understand this. Here is what I figured and it is still wrong. x= 16.50-12.96= 3.54/4.46 (SD)= 0.79 the normal distribution for 0.79 is .285. I then multiplied that by 10,ooo and the answer is: 2,850. The correct answer is 2200 according to the answer...

*November 28, 2011*

**statistics**

If scores are normally distributed with a mean of 3.06 and a standard deviation of 0.84, what percent of the scores is: (a) greater than 3.9? (b) less than 2.22? (c) between 2.22 and 3.9?

*November 28, 2011*

**statistics**

If scores are normally distributed with a mean of 3.06 and a standard deviation of 0.84, what percent of the scores is: (a) greater than 3.9? (b) less than 2.22? (c) between 2.22 and 3.9?

*November 28, 2011*

**chemistry**

An experiment in your laboratory requires 500 mL of a .0200 M solution of Na2CO3. You are given solid Na2CO3, distilled water and a 500 mL volumetric flask Describe how to prepare the required solution showing all calculations and describing each step appropriately.

*November 15, 2011*

**Chemistry**

Please help me arrange these elements in decreasing order of metallic property. I, Mg, Al, Rb, Ca Thank You

*November 14, 2011*

**physics**

Since gauge pressure=p-p_0, you must add p_0 back to the gauge pressure and then multiply by the volume and then divide by atmospheric pressure.

*November 13, 2011*

**Someone plz help me....i need help this is due now**

A set of 50 data values has a mean of 27 and a variance of 16. I. Find the standard score (z) for a data value = 19. II. Find the probability of a data value < 19. III. Find the probability of a data value > 19.

*November 12, 2011*

**Math....please help**

A set of 50 data values has a mean of 27 and a variance of 16. I. Find the standard score (z) for a data value = 19. II. Find the probability of a data value < 19. III. Find the probability of a data value > 19.

*November 12, 2011*

**Math**

A set of 50 data values has a mean of 27 and a variance of 16. I. Find the standard score (z) for a data value = 19. II. Find the probability of a data value < 19. III. Find the probability of a data value > 19.

*November 12, 2011*

**Math**

Find the probability of a data value < 19.

*November 12, 2011*

**MATH**

Assume that the population of heights of male college students is approximately normally distributed with mean of 72.15 inches and standard deviation of 6.39 inches. A random sample of 96 heights is obtained. Show all work. (A) Find P (x > 73.25) (B) Find the mean and ...

*November 11, 2011*

**MATH**

Answer the following: (A) Find the binomial probability P(x = 4), where n = 12 and p = 0.30. (B) Set up, without solving, the binomial probability P(x is at most 4) using probability notation. (C) How would you find the normal approximation to the binomial probability P(x = 4...

*November 11, 2011*

**MATH**

A set of 50 data values has a mean of 27 and a variance of 16. I. Find the standard score (z) for a data value = 19. II. Find the probability of a data value < 19. III. Find the probability of a data value > 19.

*November 11, 2011*

**MATH**

sure what question?

*November 11, 2011*

**MATH**

Construct both an ungrouped and a grouped frequency distribution for the data given below: 207 211 204 208 202 203 211 202 205 212 210 212 204 199 204 201 213 200 204 207

*November 11, 2011*

**MATH**

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 ...

*November 11, 2011*

**MATH**

(A) Classify the following as an example of nominal, ordinal, interval, or ratio level of measurement, and state why it represents this level: zip codes for the state of Pennsylvania (B) Determine if this data is qualitative or quantitative: Nationality (C) In your own line of...

*November 11, 2011*

**math**

rectangular roof of hospital has width of 80ft, and area of 16,000sq ft. what is length and perimeter of roof

*November 10, 2011*

**Math**

For the table that follows, answer the following questions: x y 1 -8 2 -11 3 -14 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 ...

*November 10, 2011*

**Math**

Rank the following data in increasing order and find the positions and values of both the 39th percentile and 67th percentile. 5 9 9 0 7 2 5 6 9 1 0 6

*November 10, 2011*

**Math**

The following data lists the average monthly snowfall for January in 15 cities around the US: 42 45 8 18 45 15 31 46 3 33 2 6 32 47 36 Find the mean, variance, and standard deviation.

*November 10, 2011*

**Math**

Given the following frequency distribution, find the mean, variance, and standard deviation. Class Frequency 31-33 18 34-36 25 37-39 22 40-42 9 43-45 20

*November 10, 2011*

**Math**

Given the following frequency distribution, find the mean, variance, and standard deviation. Class Frequency 31-33 18 34-36 25

*November 10, 2011*

**MATH...PLZ HELP**

Given a level of confidence of 99% and a population standard deviation of 13, answer the following: (A) What other information is necessary to find the sample size (n)? (B) Find the Maximum Error of Estimate (E) if n = 61. Show all work.

*November 6, 2011*

**Chemistry**

If there is a radiation that has a half life of 10 days and we have it for 110 days, what will be the fraction of radiation left?

*November 6, 2011*

**Physics**

A ball player hits a home run, and the baseball just clears a wall 17.0 m high located 124.0 m from home plate. The ball is hit an an angle of 35° to the horizontal, and air resistance is negligible. Assume the ball is hit at a height of 1.0 m above the ground. (a) What is...

*November 6, 2011*

**Adverbs and other parts of speech**

which one of the following words phrases if the superlative form of an adjective? A.Less B.Slower C.Most active D.more rapidly

*November 4, 2011*

**chemistry**

Assume that you have 2.10 of the deadly gas hydrogen cyanide, . What is the volume of the gas at STP?

*November 2, 2011*

**General Chemistry**

c3h8+5o2 3co2+4h2o How many kg of propane only is in a 20lb tank?

*October 30, 2011*

**Chemistry**

I got that delta H=-24.4 and delta G=-24.3... But keep getting the equilibrium constant (K) wrong... Can someone please help...

*October 30, 2011*

**Chemistry**

a. Calculate the delta H, delta G, and equilibrium constant for the reaction of methane with Cl2 to give CH3Cl and HCl. Use the following information for your calculations: Bond Dissociation Energies: CH3-H (104.8kcal/mol), Cl-Cl(59.0 kcal/mol), CH3-Cl(85.0 kcal/mol), and H-Cl...

*October 30, 2011*

**math**

give the answer to two decimal places: 89 / 43 =

*October 30, 2011*

**outline writing**

I need help writing an outline for what I have written here. I would like to do my assignment of Microbes, more to the point on how microbes help us. When most people think of microbes they think for bad bacteria or the ugly side of what microbes does. I have been researching ...

*October 30, 2011*

**Microbiology**

I need help writing an outline for what I have written here. I would like to do my assignment of Microbes, more to the point on how microbes help us. When most people think of microbes they think for bad bacteria or the ugly side of what microbes does. I have been researching ...

*October 30, 2011*

**Can u help me Ms. Sue...Stats**

okay thank u

*October 25, 2011*

**Can u help me Ms. Sue...Stats**

oh...its okay...do u know who can help me? no one seems to be helping me :(

*October 25, 2011*

**Can u help me Ms. Sue...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*

**Can u plz help me PsyDag?? 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*

**Is this right?? Stats....**

great i wasn't so sure about the last 2 thank you :)

*October 25, 2011*

**Is this right?? Stats....**

Classify the following as discrete or continuous random variables. (A) The time it takes to run a marathon (B) The number of fractions between 1 and 2 (C) A pair of dice is rolled, and the sum to appear on the dice is recorded (D) The length of a broad jump I got: (A) ...

*October 25, 2011*

**Is this right?? Stats....**

How many green elements are required to make this a legitimate probability distribution if there are a total of 50 elements in this sample? x red blue orange brown green P(x) 0.20 0.16 0.28 0.24 Would it be 0.12??

*October 25, 2011*

**PLZ help!! 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*

**Stats**

How many green elements are required to make this a legitimate probability distribution if there are a total of 50 elements in this sample? x red blue orange brown green P(x) 0.20 0.16 0.28 0.24 Would it be 0.11??

*October 24, 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 24, 2011*

**Stats**

Classify the following as discrete or continuous random variables. (A) The time it takes to run a marathon (B) The number of fractions between 1 and 2 (C) A pair of dice is rolled, and the sum to appear on the dice is recorded (D) The length of a broad jump I got: (A) ...

*October 24, 2011*

**Stats**

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. I'm so lost....

*October 24, 2011*

**PLZ HELP....STATS**

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 23, 2011*

**NEED HELP PLZ!!! STATS**

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 23, 2011*

**Stats**

USA snapshot presented a bar graph depicting business travelers’ impression of wait times in airport security lines over the past 12 months. Statistics were derived from Travel Industry Association of American Business Traveler Survey of 2034 respondents. Is this a ...

*October 23, 2011*

**Stats**

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 23, 2011*

**Stats**

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 23, 2011*

**Stats**

Oh....I understand a little better now...thank you!

*October 20, 2011*

**Stats**

The linear correlation coefficient is a numerical value that ranges from -1.00 to +1.00. Describe in a sentence or two the meaning of each of these correlation coefficients: a) -1.00 b) +1.00

*October 20, 2011*

**Statistics**

So they are all probability distributions?

*October 20, 2011*

**Statistics**

USA snapshot presented a bar graph depicting business travelers’ impression of wait times in airport security lines over the past 12 months. Statistics were derived from Travel Industry Association of American Business Traveler Survey of 2034 respondents. Is this a ...

*October 20, 2011*

**Statistics**

The following data lists the average monthly snowfall for January in 15 cities around the US: 29 26 6 46 17 34 15 45 19 43 37 6 9 33 37 Find the mean, variance, and standard deviation.

*October 17, 2011*

**Plz help me Sue!!**

oh....so i get x = 53??

*October 16, 2011*

**Plz help me Sue!!**

Did i do that correctly??

*October 16, 2011*

**Plz help me Sue!!**

81 = (x + 352)/5 81 = 352x/5 81 = 70.4x x = 1.15??

*October 16, 2011*

**Plz help me Sue!!**

Starting with the data values 70 and 100, add three data values to the sample so that the mean is 81, the median is 91, and the mode is 91. How do i do this??

*October 16, 2011*

**Statistics**

Starting with the data values 70 and 100, add three data values to the sample so that the mean is 81, the median is 91, and the mode is 91. How do i do this??

*October 16, 2011*

**Stats....plz help....**

can u plz help me with the other problem i posted? i need help so bad! thank u!!

*October 16, 2011*

**Stats....plz help....**

ok thank u!!

*October 16, 2011*

**Stats....plz help....**

5.04? but how did u come up with multiplying it by 9? because it's the highest number?

*October 16, 2011*

**Stats....plz help....**

001136688999??

*October 16, 2011*

**Stats....plz help....**

Rank the following data in increasing order and find the position and value of the 56th percentile. Please show all of your work. 0 1 6 8 9 9 8 6 3 1 0 9 How do i find the position and value of the 56th percentile??

*October 16, 2011*

**Math-confused...plz help**

I. Use Chebyshev’s theorem to find what percent of the values will fall between 183 and 227 for a data set with a mean of 205 and standard deviation of 11. II. Use the Empirical Rule to find what two values 99.7% of the data will fall between for a data set with a mean of...

*October 16, 2011*

**Please tell me if i did this correct**

Given the following frequency distribution, find the mean, variance, and standard deviation. Please show all of your work. Errors Frequency 51-53 9 54-56 19 57-59 16 60-62 24 63-65 25 This is what I got: Mean = 59.19 Variance = 1.43 Standard Deviation = 2.05

*October 16, 2011*

**Stats**

still confused....

*October 15, 2011*

**Stats**

Start with x=75 and add four x values to make a smaple of five data such that the standard deviation of these data equals 0.

*October 15, 2011*

**Stats**

so the SD = 30??

*October 15, 2011*

**Stats**

V = 30^2 = 900??

*October 15, 2011*

**Stats**

A set of 50 data values has a mean of 15 and a variance of 36. Find the standard score of a data value = 30

*October 15, 2011*

**Stats**

001136688999?? How do I find the position and value of the 56th percentile?

*October 15, 2011*

**Stats**

Rank the following data in increasing order and find the position and value of the 56th percentile. Please show all of your work. 0 1 6 8 9 9 8 6 3 1 0 9

*October 15, 2011*

**Stats**

yay!! thank u!!

*October 15, 2011*

**Stats**

Z = 64-51/5.0 = 13/5.0 = 2.6 Z = 47-51/5.0 = -4/5.0 = -0.8 Is this correct?

*October 15, 2011*

**Stats**

A Math test has a mean of 51 and standard deviation of 5.0. Find the corresponding z scores for: I. a test score of 64 II. a test score of 47

*October 15, 2011*

**Stats**

okay so the first would be 0.75 correct? the second one would be 3 = -16.46 -3 = -16.46 is this correct?

*October 15, 2011*

**Stats**

1. Z = (s-205)/11 = 205/11 = 18.63??? This one confuses me 2. I have no idea how to do this.... Please help!!

*October 15, 2011*

**Stats**

I. Use Chebyshev’s theorem to find what percent of the values will fall between 183 and 227 for a data set with a mean of 205 and standard deviation of 11. II. Use the Empirical Rule to find what two values 99.7% of the data will fall between for a data set with a mean of...

*October 15, 2011*

**Stats.....plz help me.....**

Given the following frequency distribution, find the mean, variance, and standard deviation. Please show all of your work. Errors Frequency 51-53 9 54-56 19 57-59 16 60-62 24 63-65 25

*October 14, 2011*

**Math**

How are z scores and the "empirical rule" related?

*October 13, 2011*