# Posts by vanessa

Total # Posts: 899

**math (9)**

Find the area of the region enclosed by these graphs and the vertical lines x = 0 and x = 3 f(x)=-x^2+2x+4 g(x)=-x+4

*April 23, 2014*

**math (8)**

Find the area of the region enclosed by these graphs and the vertical lines x = 3 and x = 5 f(x)=x^2+5 g(x)=1

*April 23, 2014*

**statistics (7)**

The average cost per night of a hotel room in New York City is $273 (SmartMoney, March 2009). Assume this estimate is based on a sample of 45 hotels and that the sample standard deviation is $65. a. With 95% confidence, what is the margin of error (to 2 decimals)? b. What is ...

*April 23, 2014*

**statistics (6)**

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample of 50 business travelers is selected and each traveler is asked to provide a ...

*April 23, 2014*

**statistics (4)**

For a t distribution with 16 degrees of freedom, find the area, or probability, in each region. a. To the right of 2.120. (Use 3 decimals.)

*April 23, 2014*

**statistics (10)**

Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $30,000 and $45,000. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. What is the planning value ...

*April 23, 2014*

**statistics (10)**

Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $30,000 and $45,000. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. What is the planning value ...

*April 22, 2014*

**statistics (7)**

Hello, Thanks for your help the answers you got are the same as mine but the website where I do my homework says it is wrong. Can you help me out please?

*April 22, 2014*

**statistics (7)**

The average cost per night of a hotel room in New York City is $273 (SmartMoney, March 2009). Assume this estimate is based on a sample of 45 hotels and that the sample standard deviation is $65. a. With 95% confidence, what is the margin of error (to 2 decimals)? b. What is ...

*April 22, 2014*

**statistics (4)**

For a t distribution with 16 degrees of freedom, find the area, or probability, in each region. a. To the right of 2.120. (Use 3 decimals.)

*April 22, 2014*

**statistics (6)**

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample of 50 business travelers is selected and each traveler is asked to provide a ...

*April 22, 2014*

**Statistics PLEASE HELP ME!**

The Wall Street Journal reported that automobile crashes cost the United States $162 billion annually (The Wall Street Journal, March 5, 2008). The average cost per person for crashes in the Tampa, Florida, area was reported to be $1599. Suppose this average cost was based on ...

*April 22, 2014*

**statistics**

Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $30,000 and $45,000. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. What is the planning value ...

*April 21, 2014*

**statistics**

How large a sample should be selected to provide a 95% confidence interval with a margin of error of 10 (to the nearest whole number)? Assume that the population standard deviation is 40.

*April 21, 2014*

**statistics**

The average cost per night of a hotel room in New York City is $273 (SmartMoney, March 2009). Assume this estimate is based on a sample of 45 hotels and that the sample standard deviation is $65. a. With 95% confidence, what is the margin of error (to 2 decimals)? b. What is ...

*April 21, 2014*

**statistics**

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample of 50 business travelers is selected and each traveler is asked to provide a ...

*April 21, 2014*

**statistics**

For a t distribution with 16 degrees of freedom, find the area, or probability, in each region. a. To the right of 2.120. (Use 3 decimals.) b. To the left of 1.337. (Use 2 decimals.) c. To the left of -1.746. (Use 2 decimals.) d. To the right of 2.583. (Use 2 decimals.) e. ...

*April 21, 2014*

**statistics**

The Wall Street Journal reported that automobile crashes cost the United States $162 billion annually (The Wall Street Journal, March 5, 2008). The average cost per person for crashes in the Tampa, Florida, area was reported to be $1599. Suppose this average cost was based on ...

*April 21, 2014*

**statistics**

A simple random sample of 40 items resulted in a sample mean of 25. The population standard deviation is 5. a. What is the standard error of the mean (to 2 decimals)? b. At 95% confidence, what is the margin of error (to 2 decimals)?

*April 21, 2014*

**Statistics Emergency please**

Thanks for your help I really appreciate it.

*April 17, 2014*

**Statistics Emergency please**

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)What is the probability ...

*April 17, 2014*

**Statistics Emergency please**

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 17, 2014*

**Math emergency I have 10 minutes to submit it.**

Evaluate the definite integral. (e^x)/(7 + e^x)dx between (0,2)

*April 16, 2014*

**Math emergency I have 10 minutes to submit it.**

Evaluate the definite integral. 9x e^(x^2)dx between (0,3)

*April 16, 2014*

**Math emergency I have 10 minutes to submit it.**

Evaluate the definite integral. x sqrt(13 x^2 + 36)dx between (0,1)

*April 16, 2014*

**Math**

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*

**Math**

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 16, 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 16, 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 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*