Wednesday

October 1, 2014

October 1, 2014

Total # Posts: 745

**Statistics**

The College Board reported the following mean scores for the three parts of the Scholastic Aptitude Test (SAT) (The World Almanac, 2009): Assume that the population standard deviation on each part of the test is = 100. a. What is the probability a sample of 90 test takers will...
*April 16, 2014*

**Grade 12 Chemistry**

When 50.0 mL of 1.0 mol/L hydrochloric acid is neutralized completely by 75.0 mL of 1.0 mol/L sodium hydroxide in a coffee-cup calorimeter, the temperature of the total solution changes from 20.2 to 25.6. Determine the quantity of energy transferred, q, and state whether the ...
*April 15, 2014*

**statistics**

People end up tossing 12% of what they buy at the grocery store (Reader's Digest, March 2009). Assume this is the true population proportion and that you plan to take a sample survey of 540 grocery shoppers to further investigate their behavior. a.Show the sampling ...
*April 15, 2014*

**statistics**

The College Board reported the following mean scores for the three parts of the Scholastic Aptitude Test (SAT) (The World Almanac, 2009): Assume that the population standard deviation on each part of the test is = 100. a. What is the probability a sample of 90 test takers will...
*April 15, 2014*

**statistics**

Suppose a random sample of size 50 is selected from a population with σ = 10. Find the value of the standard error of the mean in each of the following cases (use the finite population correction factor if appropriate). a. The population size is infinite (to 2 decimals). ...
*April 15, 2014*

**statistics**

The American Association of Individual Investors (AAII) polls its subscribers on a weekly basis to determine the number who are bullish, bearish, or neutral on the short-term prospects for the stock market. Their findings for the week ending March 2, 2006, are consistent with ...
*April 15, 2014*

**Math**

It still says it is wrong. =/
*April 15, 2014*

**Math**

Find the average value of the function f over the interval [-1, 2]. f(x)=1-x^2
*April 15, 2014*

**Math**

The thing is that I did get 7/8(log9-log1) I got 7/8(log8-log1). but thanks for your help.
*April 14, 2014*

**Math**

Find the average value of the function f over the indicated interval [0, 8]. f(x) = 7/(x + 1) I keep getting the wrong answer.
*April 14, 2014*

**Math**

Find the average value of the function f over the interval [-1, 2]. f(x) = 1-x^2
*April 14, 2014*

**Math**

Find the average value of the function f over the interval [-1, 2]. f(x) = 1-x^2
*April 14, 2014*

**Math**

Find the average value of the function f over the indicated interval [0, 8]. f(x) = 7/(x + 1) I keep getting the wrong answer.
*April 14, 2014*

**statistics**

People end up tossing 12% of what they buy at the grocery store (Reader's Digest, March 2009). Assume this is the true population proportion and that you plan to take a sample survey of 540 grocery shoppers to further investigate their behavior. a. Show the sampling ...
*April 14, 2014*

**statistics**

Assume that the population proportion is .55. Compute the standard error of the proportion, ( ), for sample sizes of 100, 200, 500, and 1000 (to 4 decimals). a. 100? b. 200? c. 500? d. 1000?
*April 14, 2014*

**statistics**

The College Board reported the following mean scores for the three parts of the Scholastic Aptitude Test (SAT) (The World Almanac, 2009): Assume that the population standard deviation on each part of the test is = 100. a. What is the probability a sample of 90 test takers will...
*April 14, 2014*

**statistics**

Suppose a random sample of size 50 is selected from a population with σ = 10. Find the value of the standard error of the mean in each of the following cases (use the finite population correction factor if appropriate). a. The population size is infinite (to 2 decimals). ...
*April 14, 2014*

**statistics**

Many drugs used to treat cancer are expensive. BusinessWeek reported on the cost per treatment of Herceptin, a drug used to treat breast cancer (BusinessWeek, January 30, 2006). Typical treatment costs (in dollars) for Herceptin are provided by a simple random sample of 10 ...
*April 14, 2014*

**Math**

A car moves along a straight road in such a way that its velocity (in feet per second) at any time t (in seconds) is given by v(t) = 3t sqrt(64−t^2) (0 ≤ t ≤ 8). Find the distance traveled by the car in the 8 sec from t = 0 to t = 8.
*April 14, 2014*

**Math**

Based on a preliminary report by a geological survey team, it is estimated that a newly discovered oil field can be expected to produce oil at the rate of R(t) = 300t^2/(t^3 + 32)+5 (0 ≤ t ≤ 20) thousand barrels/year, t years after production begins. Find the ...
*April 14, 2014*

**Math**

Find the average value of the function f over the interval [-1, 2]. f(x) = 1 - x^2
*April 14, 2014*

**Math**

Find the average value of the function f over the indicated interval [0, 8]. f(x) = 7/(x + 1)
*April 14, 2014*

**Math**

Find the average value of the function f over the interval [0, 8]. f(x) = 5e^-x
*April 14, 2014*

**Math**

Find the indefinite integral. (e^(9 x))/(2 + e^(9 x)) dx
*April 13, 2014*

**Math**

Evaluate the following definite integral. 5(1 + 1/u + 1/u^2)du between, (5,7)
*April 13, 2014*

**Math**

Annual sales (in millions of units) of pocket computers are expected to grow in accordance with the following function where t is measured in years, with t = 0 corresponding to 1997. f(t) = 0.18t^2 + 0.16t + 2.64 How many pocket computers will be sold over the 2 year period ...
*April 13, 2014*

**Math**

Evaluate the following definite integral. 5(1 + 1/u + 1/u^2)du between (5,7)
*April 10, 2014*

**Math**

Annual sales (in millions of units) of pocket computers are expected to grow in accordance with the following function where t is measured in years, with t = 0 corresponding to 1997. f(t) = 0.18t^2 + 0.16t + 2.64 (0<=t<=2) How many pocket computers will be sold over the ...
*April 10, 2014*

**Math**

The management of Ditton Industries has determined that the daily marginal revenue function associated with selling x units of their deluxe toaster ovens is given by the following where R '(x) is measured in dollars/unit. R'(x)= -0.1x + 40 (a) Find the daily total ...
*April 10, 2014*

**Math**

Evaluate the following definite integral. sqrt(11 x)(sqrt(x) + sqrt(11)) dx between(0,1)
*April 10, 2014*

**statistics; emergency please help me**

Assume a binomial probability distribution has p = .60 and n = 200. a. What is the probability of 100 to 110 successes (to 4 decimals)? b. What is the probability of 130 or more successes (to 4 decimals)?
*April 10, 2014*

**statistics; emergency please help me**

Given that z is a standard normal random variable, compute the following probabilities (to 4 decimals). a. P(z -1.5) b. P(z -2.5)
*April 10, 2014*

**math/ratios**

If there are 5 cats and 4 dogs how would I create a ratio bar? Help!
*April 10, 2014*

**Math**

Find the indefinite integral. (e^(4 x) + e^(-5 x)) dx
*April 9, 2014*

**Math**

Thanks Reiny for all your help, I really appreciate it.
*April 9, 2014*

**Math**

Find the indefinite integral. x^2(5 x^3 + 9)^3 dx
*April 9, 2014*

**Math**

The average student enrolled in the 20-wk Court Reporting I course at the American Institute of Court Reporting progresses according to the rule below where 0 t 20, and N'(t) measures the rate of change in the number of words/minute dictation the student takes in machine ...
*April 9, 2014*

**Math**

Find the function f, given that the slope of the tangent line at any point (x,f(x)) is f '(x) and that the graph of f passes through the given point. f '(x)=6(2x-7)^5 at (4, 3/2)
*April 9, 2014*

**Math**

Carlota Music Company estimates that the marginal cost of manufacturing its Professional Services guitars in dollars/month by the following. This model assumes that the level of production is x guitars/month. C '(x) = 0.007x + 130 The fixed costs incurred by Carlota are $...
*April 9, 2014*

**statistics**

Collina’s Italian Café in Houston, Texas, advertises that carryout orders take about 25 minutes (Collina’s website, February 27, 2008). Assume that the time required for a carryout order to be ready for customer pickup has an exponential distribution with a ...
*April 9, 2014*

**statistics; emergency please help me**

This is what I got too but the web where I do my homework says it is wrong.
*April 8, 2014*

**statistics; emergency please help me**

Given that z is a standard normal random variable, compute the following probabilities (to 4 decimals). c. P(z -1.5) d. P(z -2.5)
*April 8, 2014*

**statistics; emergency please help me**

Assume a binomial probability distribution has p = .60 and n = 200. c. What is the probability of 100 to 110 successes (to 4 decimals)? d.What is the probability of 130 or more successes (to 4 decimals)?
*April 8, 2014*

**statistics; emergency please help me**

Collina’s Italian Café in Houston, Texas, advertises that carryout orders take about 25 minutes (Collina’s website, February 27, 2008). Assume that the time required for a carryout order to be ready for customer pickup has an exponential distribution with a ...
*April 8, 2014*

**Math**

I agree it quadruples.
*April 8, 2014*

**Statistics PLEASE HELP ME!**

Collina’s Italian Café in Houston, Texas, advertises that carryout orders take about 25 minutes (Collina’s website, February 27, 2008). Assume that the time required for a carryout order to be ready for customer pickup has an exponential distribution with a ...
*April 7, 2014*

**Economic/Statistics**

Collina’s Italian Café in Houston, Texas, advertises that carryout orders take about 25 minutes (Collina’s website, February 27, 2008). Assume that the time required for a carryout order to be ready for customer pickup has an exponential distribution with a ...
*April 7, 2014*

**statistics**

Collina’s Italian Café in Houston, Texas, advertises that carryout orders take about 25 minutes (Collina’s website, February 27, 2008). Assume that the time required for a carryout order to be ready for customer pickup has an exponential distribution with a ...
*April 7, 2014*

**Math**

Thanks for the help.
*April 7, 2014*

**Math**

This is what I got too, but it says that my answer is wrong.
*April 7, 2014*

**Math**

The percentage of a certain brand of computer chips that will fail after t years of use is estimated to be P(t) = 100(1 − e−0.12t ). What percentage of this brand of computer chips are expected to be usable after 3 years? (Round your answer to one decimal place.)
*April 7, 2014*

**Math**

ok I got now. Thank you so much for your help, I appreciate it.
*April 7, 2014*

**Math**

I got t=70 and it still says it is wrong.
*April 7, 2014*

**Math**

This is what I got and it says it is wrong. Can you tell me what I'm doing wrong please? Thanks Q(t) = 200(.5)^(.0704t) Q '(t) = (200/14.2) (.5)^(t/14.2) so when t = 21.5 Q ' (t) = (200/14.2) (.5)^(21.5/14.2) = 4.931 g/day
*April 7, 2014*

**Math**

Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...
*April 7, 2014*

**Math**

The length (in centimeters) of a typical Pacific halibut t years old is approximately f(t) = 190(1 − 0.955e−0.25t). (b) How fast is the length of a typical 9-year-old Pacific halibut increasing? cm/yr (c) What is the maximum length a typical Pacific halibut can ...
*April 7, 2014*

**math**

The percentage of a certain brand of computer chips that will fail after t years of use is estimated to be P(t) = 100(1 − e−0.12t ). What percentage of this brand of computer chips are expected to be usable after 3 years? (Round your answer to one decimal place.)
*April 7, 2014*

**math**

The length (in centimeters) of a typical Pacific halibut t years old is approximately. (b) How fast is the length of a typical 9-year-old Pacific halibut increasing? (c) What is the maximum length a typical Pacific halibut can attain?
*April 7, 2014*

**math**

Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...
*April 7, 2014*

**statistics**

Assume a binomial probability distribution has p = .60 and n = 200. c. What is the probability of 100 to 110 successes (to 4 decimals)? d. What is the probability of 130 or more successes (to 4 decimals)?
*April 7, 2014*

**statistics**

Given that z is a standard normal random variable, compute the following probabilities (to 4 decimals). P(z -1.0) P(z -1.0) P(z -1.5) P(z -2.5) P(-3 < z 0)
*April 7, 2014*

**statistics**

Collina’s Italian Café in Houston, Texas, advertises that carryout orders take about 25 minutes (Collina’s website, February 27, 2008). Assume that the time required for a carryout order to be ready for customer pickup has an exponential distribution with a ...
*April 7, 2014*

**statistics**

Collina’s Italian Café in Houston, Texas, advertises that carryout orders take about 25 minutes (Collina’s website, February 27, 2008). Assume that the time required for a carryout order to be ready for customer pickup has an exponential distribution with a ...
*April 6, 2014*

**statistics**

Given that z is a standard normal random variable, compute the following probabilities (to 4 decimals). P(z -1.0) P(z -1.0) P(z -1.5) P(z -2.5) P(-3 < z 0)
*April 6, 2014*

**statistics**

Assume a binomial probability distribution has p = .60 and n = 200. c. What is the probability of 100 to 110 successes (to 4 decimals)? d. What is the probability of 130 or more successes (to 4 decimals)?
*April 6, 2014*

**Math**

The growth rate of Escherichia coli, a common bacterium found in the human intestine, is proportional to its size. Under ideal laboratory conditions, when this bacterium is grown in a nutrient broth medium, the number of cells in a culture doubles approximately every 30 min. (...
*April 6, 2014*

**Math**

Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...
*April 6, 2014*

**Math**

The length (in centimeters) of a typical Pacific halibut t years old is approximately. (b) How fast is the length of a typical 9-year-old Pacific halibut increasing? (c) What is the maximum length a typical Pacific halibut can attain?
*April 6, 2014*

**Math**

A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...
*April 6, 2014*

**Math**

The percentage of a certain brand of computer chips that will fail after t years of use is estimated to be P(t) = 100(1 − e−0.12t ). What percentage of this brand of computer chips are expected to be usable after 3 years? (Round your answer to one decimal place.)
*April 6, 2014*

**Math**

During a flu epidemic, the number of children in the Woodbridge Community School System who contracted influenza after t days was given by the following. Q(t) = 7000/1+249 e−0.6 t (b) How many children had the flu after 10 days?
*April 6, 2014*

**statistics**

Given that z is a standard normal random variable, compute the following probabilities (to 4 decimals). P(z -1.0) P(z -1.0) P(z -1.5) P(z -2.5) P(-3 < z 0)
*April 5, 2014*

**statistics**

Assume a binomial probability distribution has p = .60 and n = 200. a)What are the mean and standard deviation (to 2 decimals)? b)Why can the normal probability distribution be used to approximate this binomial distribution? c)What is the probability of 100 to 110 successes (...
*April 5, 2014*

**statistics**

Collina’s Italian Café in Houston, Texas, advertises that carryout orders take about 25 minutes (Collina’s website, February 27, 2008). Assume that the time required for a carryout order to be ready for customer pickup has an exponential distribution with a ...
*April 5, 2014*

**Math**

A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...
*April 5, 2014*

**Math**

During a flu epidemic, the number of children in the Woodbridge Community School System who contracted influenza after t days was given by the following. Q(t) = 7000 1+249 e−0.6 t (a) How many children were stricken by the flu after the first day? (b) How many children ...
*April 5, 2014*

**Math**

The percentage of a certain brand of computer chips that will fail after t years of use is estimated to be P(t) = 100(1 − e−0.12t ). What percentage of this brand of computer chips are expected to be usable after 3 years? (Round your answer to one decimal place.)
*April 5, 2014*

**Math**

The length (in centimeters) of a typical Pacific halibut t years old is approximately f(t) = 190(1 − 0.955e−0.25t). How fast is the length of a typical 9-year-old Pacific halibut increasing? ? cm/yr (c) What is the maximum length a typical Pacific halibut can ...
*April 5, 2014*

**Math**

The growth rate of Escherichia coli, a common bacterium found in the human intestine, is proportional to its size. Under ideal laboratory conditions, when this bacterium is grown in a nutrient broth medium, the number of cells in a culture doubles approximately every 30 min. (...
*April 5, 2014*

**math **

Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...
*April 5, 2014*

**Math**

Skeletal remains had lost 84% of the C-14 they originally contained. Determine the approximate age of the bones. (Assume the half life of carbon-14 is 5730 years. Round your answer to the nearest whole number.)
*April 5, 2014*

**Global Studies**

I was also thinking c?
*March 12, 2014*

**Global Studies**

Which of the following minerals generates the most income for British Columbia? A. lead B. zinc c. Gold d. Copper <<< One reason many British Columbians feel a link to the countries of the Pacific Rim is because more than 15% have ____ancestors. a. Hawaiian <<&...
*March 12, 2014*

**algebra **

Hoe can I solve this by using elimination method.?? 5y+2x=5x+1 3x-2y=3+3y
*February 10, 2014*

**science**

please help someone fast !!!
*December 19, 2013*

**science**

Describe how the Triassic period was a transitional time period during the Mesozoic era. Explain why the boundary between the Triassic and Jurassic periods is similar to the boundary between the Permian and Triassic periods.
*December 19, 2013*

**science**

2. Describe the two most important events in the history of animal life that occurred at the beginning and at the end of the Paleozoic era. List and briefly outline the six different periods into which the Paleozoic era is divided. so i cannot find it in my notes, and im ...
*December 19, 2013*

**Math**

Write a unit rate 250 miles for 20 miles
*November 22, 2013*

**MATH HELP**

write the equations of two different parabolas whose vertices are at (3,2).
*November 13, 2013*

**algebra**

how do you solve x+y=2?
*November 13, 2013*

**Chemistry**

Measuring the conductivity of an aqueous solution in which 0.0200 mol CH3COOH has been dissolved in 1.00 L of solution shows that 2.96 % of acetic acid molecules have ionized to CH3COO- ions and H3O+ ions. Calculate the equilibrium constant for ionization of acetic acid and ...
*November 12, 2013*

**Algerbra**

Divide (x^6-13x^3+42)/(x^3-7) Please show me how to work the problem
*October 30, 2013*

**biology**

thanks so much for the article
*October 30, 2013*

**biology**

If a person with Down syndrome marries a person without Down syndrome, is it possible for their child not to have Down syndrome? I assume that there is a 50% chance that they could have a child that will not have down syndrome. Is this correct?
*October 30, 2013*

**grade 11 biology**

Consider a germ cell of a person with Down syndrome(Trisomy 21). Explain what is happening with the arrangement of chromosome 21 inside the cell during interphase 1, Anaphase 1, Telophase 1, telophase 11. Please help, I am really stuck on this. Thank you
*October 30, 2013*

**physics**

The total volume of a new house is 800 m3. Before the heat is turned on, the air temperature inside is 10°C, and the relative humidity is 50%. After the air is warmed to 20°C, how much water vapor must be added to the air to make the relative humidity 50%? m = kg
*October 24, 2013*

**Math **

log a = 2 Find the vaule of A
*October 21, 2013*

**biology**

Stuck on this question. When infected by the Hepatitis B virus (HBV), many patients experience flu-like symptoms such as fever, loss of appetite, nausea, vomiting, and malaise. This is called acute hepatitis. During this stage, what is the HBV doing? What do you call this ...
*October 19, 2013*

**biology**

Hi there, Not sure the answer for this question. In what way is endospores stronger than bacterial cell?
*October 18, 2013*

**alegbra**

Use linear combinations to solve these systems. 5r-3s=12 3r+55=28
*October 13, 2013*

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