# Statistics

**statistics**

1. Suppose the estimate of a proportion of a normal population is to be within 0.05 using the 95% confidence level. How large a sample is required if: a. It is known from previous studies that p = 0.3? b. There is no prior knowledge of p? 2. Each of the following is a large-...

**Statistics**

It is pretty common across most schools to find the grades at the MBA level divided between A's and B's. As such, you expect the mean GPA to be around 3.50. Using the sample of 200 MBA students, conduct a one-sample hypothesis test to determine if the mean GPA is different ...

**Statistics**

1 39 63 wind speed (km h ) –1 Measurements of wind speed on a certain island were taken over a period of one year. A box-andwhisker plot of the data obtained is displayed above, and the values of the quartiles are as shown. It is suggested that wind speed can be modelled ...

**Marketing reserch**

a marketing researcher analyzing the fast food industry noticed the following restaurant in Cali was 3.30 with a standard deviation of .40. yet in Georgia the average amount spent at a fast food restaurant was 3.25 with a standard deviation of .10. what do these statistics ...

**statistics**

63% of men consider themselves baseball fans. You randomly select 10 and ask if he consider him self a baseball fan. Find the probability that the number who consider themselves baseball fans is (a) exactly 8, (b) at least (8) less than (8)

**Statistics**

College officials want to estimate the percentage of students who carry a gun, knife, or other such weapon. How many randomly selected students must be surveyed in order to be 94% confident that the sample percentage has a margin of error of 2 percentage points?

**statistics**

A recent survey showed that among 675 randomly selected subjects who completed 4 years of college, 138 smoke and 537 do not smoke. Determine a 95% confidence interval for the true proportion of the given population that smokes.

**statistics**

A simple random sample of a size n is drawn from a population that is normally distributed. The sample mean, x is found to be 110, and the sample standard deviation, s, is found to be 10. A- Construct a 95% confidence interval about u if the sample size, n, is 17

**statistics**

a repair shop believes that people travel more than 3500 miles between oil changes a random sample of 8 cars getting an oil change has average distance of 3375 standard deviation of 225 miles with alpha 0.05 is there enough evidence to support the shops claim

**Statistics**

The percentage of various colors are different for the "peanut" variety of M&M's candies, as reported on the Mars, Incorporated website. Brown: 12% Yellow: 15% Red: 12% Blue: 23% Orange: 23% Green: 15% A 14-ounce bag of peanut M&M's is randomly selected and contains 70 brown, ...

**statistics**

If I selected one player at random what would be the probability of an NBA player in the Eastern conference being less than 6 feet tall? First calculate the z-score and then use the standard normal table to find the probability.

**math**

a statistics professor plans class so carefully that the lengths of his classes are uniformly distributed between 45.0 and 55.0 minutes. find the probability that a given class period runs greater than 50.75 minutes? find the probability of selecting a class that runs greater ...

**statistic**

A statistics quiz consists of 10 multiple questions. There are four choices for each question. One student is unprepared and decides to guess the answers to every question. Assuming 70% is a passing grade, find the probability that the student will pass the quiz.

**statistics**

Consider the test of hypothesis for the equality of two population means. The sample data from the first population is: n = 10, x-bar = 52.4, s = 5. The sample data from the second population is: n = 8, x-bar = 48.2, s = 6. Both variables are normally distributed and the ...

**statistics**

A test of hypothesis is performed to determine whether the proportion of Montrealers (population 1) who want the decriminalization of marijuana is greater than the proportion of Torontonians (population 2) who want decriminalization of marijuana. A random sample of 115 ...

**statistics**

A random sample of 150 investment bankers (population 1) had thirty percent who expressed dissatisfaction with their choice of career. A random sample of 200 financial analysts (population 2) had forty-two percent who expressed dissatisfaction. In testing the hypothesis that a...

**statistics**

The Vancouver Chamber of Commerce claims that the mean cost of hotels in the downtown area of the city is less than in Edmonton. A random sample of 50 hotels in Vancouver (population 1) had a mean nightly rate of $109 with a standard deviation of $15. An independent sample of ...

**statistics**

Which of the following statements are true? (A) In testing the hypothesis for the equality of two population proportions, the acceptance region for the null hypothesis will be wider than the confidence interval for two population proportions, assuming the same value of alpha...

**statistics**

A comparison of the last year's (Population 1) versus the current year's (Population 2) shipments (in thousands of dollars) for each of six Canadian exporters is given as follows: (4.34, 4.77), (5.89, 5.16), (2.52, 2.73), (3.91, 4.39), (4.99, 5.25), (3.24, 3.80). It is assumed...

**statistics**

A VP of manufacturing claims that no more than 3% of items produced using a certain assembly line are defective. A random sample of 100 items from the assembly line had 5 defectives. At the 5% level of significance, which of the following would be part of the standardized ...

**statistics**

The Dean of a university claims that no more than 10% of the students drop out of university. She chooses a random sample of 500 students and decides that she will accept the claim only if no more than 25 of the 500 students drop out of university. In fact her claim is true - ...

**statistics**

Which of the following statements are false? (A) The t-distribution should always be used when n is small. (B) A test of hypothesis is found to have a p-value of .0682. Then one should conclude H1 if the level of significance is 10% and conclude Ho if the level of significance...

**statistics**

A study is to be conducted to determine whether the mean cost of repairing a car is more than $500. A random sample of 100 repairs is selected and the following decision rule is constructed: conclude the null hypothesis if the sample mean is less than or equal to $515, ...

**statistics**

A sample of 50 items is selected to determine whether or not to accept the hypothesis that a population means differs from a value of 20. The sample mean and standard deviation are 18 and 7, respectively. The null hypothesis is not rejected, which of the following is a ...

**math/stats**

Which of the following statements are true? (A) In a two-tail test of hypothesis for a population mean the decision rule is to reject H0 if the test statistic lies outside of the action limits. (B) A statistical test of hypothesis is performed under the assumption that the ...

**statistics**

a local content center reports that it has been experiencing a 15% rate of no shows on advanced reservations. Among 150 advanced reservations find the probability that there will be fewer than 20 no shows round the standard deviation to three decimal to work the problem

**Business statistics**

5. An Aspirin manufacturer fills bottles by weight rather than by count. Since each bottle should contain 100 tablets, the average weight per tablet should be 5 grains. Each of 100 tablets taken from a large lot is weighed, resulting in a sample average weight per tablet of 4....

**Business statistics**

4. A study of the ability of individuals to walk in a straight line (“Can We Really Walk Straight?”, Amer. J. of Physical Anthro., 1992:19-27) reported the accompanying data on cadence (strides per second) for a sample of 20 randomly selected individuals. 0.95 0.82 0.92 0....

**Business statistics**

3. Determine the t-critical value for a two-sided confidence interval in each of the following situations. a. Confidence level = 95%, df = 15 b. Confidence level = 99%, n = 5. c. Confidence level = 95%, n = 15 d. Significance level = 0.01, df = 37

**Business statistics**

2. Each of the following is a large-sample confidence interval for μ, the mean resonance frequency (HZ) for all tennis rackets of a certain type. (114.4, 115.6), (114.1, 115.9) a. What is the value of the sample mean resonance frequency? b. Both intervals were calculated ...

**Business statistics**

1. Suppose the estimate of a proportion of a normal population is to be within 0.05 using the 95% confidence level. How large a sample is required if: a. It is known from previous studies that p = 0.3? b. There is no prior knowledge of p?

**statistics**

4.The College Boards, which are administered each year to many thousands of high school students, are scored so as to yield a mean of 500 and standard deviation of 100. These scores are close to be normally distributed. a. What percentage of the scores can be expected ... ... ...

**statistics**

A cereal company claims that 2 in every 15 boxes win a prize. What is the probability that you do not win a prize three times in a row?

**Statistics**

The Economic Policy Institute periodically issues reports on wages of entry-level workers. The institute reported that entry-level wages for male college graduates were $21.68 per hour and for female college graduates were $18.80 per hour in 2011 (Economic Policy Institute ...

**Probability & Statistics**

To help consumers assess the risks they are taking, the Food and Drug Administration (FDA) publishes the amount of nicotine found in all commercial brands of cigarettes. A new cigarette has recently been marketed. The FDA tests on this cigarette yielded mean nicotine content ...

**Probability and Statistcis**

Students from a statistics class were asked to record their height in inches. The heights ( as recorded) were: 65, 72, 68, 64, 60, 55, 73, 71, 52, 63, 61, 74, 69, 67, 74, 50, 4, 75, 67, 62, 66, 80, 64, 65 Find five number summary.

**Statistics**

I have a bunch of questions to work on with this specific scenario but I was hoping someone can just help me get started on the first one because I'm having trouble getting started and I'll do the rest on my own.Thanks for any help! In a southern state, it was revealed that 5...

**Intro statistics**

A bag contains 7 red, 6 orange, and 9 green jellybeans. What is the probability of reaching into the bag and randomly withdrawing 11 jelly beans such that the number of red ones is 7 the number of orange ones is 1 and the number of green ones is 3?

**Economics**

China's slowdown Jan 20th 2015, 10:26 by S.R. | SHANGHAI MUCH of the analysis of China’s 2014 GDP data, which the government published today, has focused on the economy’s slowdown That is, on one level, understandable. Growth of 7.4% was China’s weakest in 24 years (see ...

**statistics**

Average entry level salaries for college graduates with mechanical engineering degrees and electrical engineering degrees are believed to be approximately the same. A recruiting office thinks that the average mechanical engineering salary is actually lower than the average ...

**journalism check answers**

What is satire's underlying goal? to sell newspapers to shock people to get people to think c Many young people today get their news from which of the following unlikely sources? comedy shows such as "The Daily Show" their friends video games B Which of the following would not...

**statistics**

There is a multiple choice exam with 24 questions, and five options each. If i guess every question, what is the probability that i will get exactly 15 correct.

**statistics**

Does a correlation ever prove causation? (For any subject/field?)

**statistics**

(10 pts) Using diaries for many weeks, a study on the lifestyles of visually impaired students was conducted. The students kept track of many lifestyle variables including how many hours of sleep obtained on a typical day. Researchers found that visually impaired students ...

**Statistics**

What do SEM (standard error of the mean) error bars tell you? How would you describe them in a figure caption for a graph? I know what regular error bars are, but I can't find any information on SEM error bars!

**Statistics**

A researcher predicts that watching a film on institutionalization will change students’ attitudes about chronically mentally ill patients. The researcher randomly selects 36 students, shows them the film, and gives them a questionnaire about their attitudes. The mean score ...

**statistics**

In a certain lottery, five different numbers between 1 and 31 inclusive are drawn. These are the winning numbers. To win the lottery, a person must select the correct 5 numbers in the same exact order in which they were drawn. What is the probability of winning?

**statistics**

According to a college survey, 22% of all students work full time. Find the mean and standard deviation for the number of students who work full time in samples of size 16.

**statistics**

An unprepared student makes random guesses for the ten true-false questions on a quiz. Find the probability that there is at least one correct answer.

**statistics**

The mayor of the town of Quahog, Rhode Island, Adam West, conducted a study to determine the mean household income of his constituents. The study surveyed 500 households and determined that the sample mean was $30,000. The population standard deviation is $4,800. If a ...

**statistics**

A certain type of dvd player is sold at just two stores. 30% of sales are from store A and 70% of sales are from store B. 2.7% of the dvd players sold at store A are defective while 3.7% of the dvd players sold at store B are defective. If Kate receives one of these dvd ...

**Business Statistics**

A firm claims that only 10% of it's accounts receivables are over 30 days past due. The bank that supplies working capital or interim loans to the firms is suspect of the figure and accordingly takes a random sample of 100 accounts of the firm. Find the probability that the ...

**Business Statistics**

A marketing class is engaged in a project to estimate the proportion of homes receiving both HBO and Showtime cable service. The class plans to use a confidence coefficient of 0.95 and a maximum error of the estimate equal to 0.10. Determine the sample size for the class to use.

**Business Statistics**

A filling machine is designed to fill soda bottles with 16 ounces of soda. The distribution for the weight of the bottles is normal. Twenty bottles are selected and weighed. The sample mean is 15.3 ounces and sample standard deviation is 1.5 ounces. Develop a 90% confidence ...

**Business Statistics**

There are 300 students enrolled in Business Statistic. Historically, exam scores are normally distributed with a standard deviation of 30.9. Your instructor randomly selected a sample of 30 examinations and finds a mean of 74.2. Determine a 90% confidence interval for the mean...

**Statistics**

The average SAT score for the 300 students accepted at Tiny College this year is 1,050 with a standard deviation of 275. If a random sample of 40 students is selected from this class, what is the probability that the average SAT score will be greater than 1,000?

**Statistics**

A firm claims that only 10% of its accounts receivables are over 30 days past due. The bank that supplies working capital or interim loans to the firm is suspect of the figure and accordingly takes a random of 100 accounts of the firm. Find probability that the sample ...

**Statistics**

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes. what is the probability that a). it will take a technician less than 10 minutes to fix a computer problem? b) it will take a technician between 10 to 15 minutes to ...

**Statistics**

the age of costumers for a particular retail store follows a normal distribution with a mean of 37.5 years and a standard deviation of 7.6 years. what is the probability that the next costumer who enters the store will be less than 42 years old?

**Statistics**

in 2000, the averages change of tax preparation was $95. Assuming a normal distribution and a standard deviation of $10. What proportion of tax preparation fees were more than $95.

**Statistics**

How many different ways can you put 3 distinguishable things in 10 boxes?

**statistics**

A credit card company estimates that the average credit card balance of Americans is $3,210. A statistics student wants to know whether this is true for citizens of her home town. Which hypothesis test would be most appropriate for addressing this question? One sample z-test ...

**statistics**

A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study 395 babies were born, and 316 of them were girls. Use the sample data to construct a 99% confidence interval estimate of the percentage of girls born. Based on the result, ...

**Statistics**

80. Florida State University has 14 statistics classes scheduled for its Summer 2013 term. One class has space available for 30 students, eight classes have space for 60 students, one class has space for 70 students, and four classes have space for 100 students. a. What is the...

**Statistics - Can anybody help me?**

A Particular pain relieving medicine has a decay rate of 24% an hour. A patient was given a dose of the medicine 5 hours ago and there is currently 74mg of the medicine in the patients bloodstream. Q: What was the Origional dose of the medicine? ________ milligrams. Q How long...

**Statistics**

A Particular pain relieving medicine has a decay rate of 24% an hour. A patient was given a dose of the medicine 5 hours ago and there is currently 74mg of the medicine in the patients bloodstream. Q: What was the Origional dose of the medicine? ________ milligrams. Q How long...

**Statistics**

Good Afternoon, Hope everyone will have a nice weekend. I am sorry to bother you all, but I am failing statistic. Can someone give me an example of this and example of a regression hypothesis. Thank you

**statistics/probability**

An engineer is going to redesign an ejection seat for an airplane. The seat was designed for pilots weighing between 130 lb and 181 lb. The new population of pilots has normally distributed weights with a mean of 135 and a standard deviation of 25.1 lb. If a pilot is randomly ...

**statistics**

The mean (μ) of the scale is 83 and the standard deviation (σ) is 10. Assuming that the scores are normally distributed, what is the PROBABILITY that a score falls below 72?

**statistics**

The average age of doctors in certain hospital is 43 years old. Suppose distribution of ages is normal and the standard deviation is 8.0 years. If 25 doctors is chosen at random for a committee, find the probability the average age for those doctors is less than 43.8 years. ...

**statistics**

A casting director wishes to find one male and one female to cast is his play. If he plans to audition 5 males and 7 females, in how many different ways can this be done? DO NOT put a comma in your response.

**Statistics**

Shopping Outlet A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below. x 0 1 2 3 4 p(x) 0.05 0.35 0.25 0.20 0.15 What is the probability that shoppers are just window shopping and not entering any ...

**Statistics**

In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal distribution to estimate the requested probabilities. More than a decade ago, high levels of lead in the blood put 87% of children at risk. A concerted ...

**Elementary Statistics**

"Scores on the Wechsler IQ test approximate a normal curve with a mean of 100 and a standard deviation of 15. b. What percentage of IQ scores are below 74?" I've been working at this for a while now, but when I solve for the z-score, I keep getting a negative number. z=(74-100...

**statistics**

Z-test. How to find critical value for one tail test?

**statistics - can someone please Help me**

I have tried for days to figure out how to work this problem. Please help show me how to find the answer. A particular radioactive isotope decays from 210 mg to 182.7 mg in 15 days. Find the half life of the isotope. I can not find any problem that is similar. everything i ...

**statistics**

How to find p value? If test statistic is -0.37, will the p value be 0.3557?

**statistics**

I have tried for days to figure out how to work this problem. Please help show me how to find the answer. A particular radioactive isotope decays from 210 mg to 182.7 mg in 15 days. Find the half life of the isotope.

**statistics**

A jar contains 3 nickels and 2 dimes. You reach in and randomly select 2 coins. Let x represent the value of the two coins in cents. Find the expected value and standard deviation of x

**statistics**

Determine whether the description corresponds to an observational study or an experiment. Research is conducted to determine if there is a relation between kidney function in adults and childhood-onset diabetes.

**statistics**

Based on a study of IQs of men and women who play chess competitively, a researcher concludes that playing chess causes people to become smarter. Do you agree with this conclusion?

**Statistics**

A history class is comprised of 5 female and 8 male students. If the instructor of the class randomly chooses 8 students from the class for an oral exam, what is the probability that 2 female students and 6 male students will be selected? Round your answer to decimal places.

**problem and statistics**

In a random sample of 10 on-line statistics students, information was collected about their minutes studied and their chapter test scores. X is the minutes studied, and Y is the test score. x : {20,30,45,60,80,90,45,120,90,70} y: {50,45,55,70,80,90,80,100,95,85} Is this ...

**statistics**

An online site presented this question, 'Would the recent norovirus outbreak deter you from taking a cruise?' Among 34,327 people who responded, 66% answered 'yes'. Use the sample data to construct a 95% confidence interval estimate for the proportion of the population of all ...

**Statistics**

In the week before and the week after a holiday, there were 12,000 total deaths, and 5916 of them occurred in the week before the holiday. a. Construct a 95% confidence interval estimate of the proportion of deaths in the week before the holiday to the total deaths in the week...

**Healthcare Statistics**

As a data collection specialist at the National Institutes of Health (NIH), you have been involved in a research study conducted over the past year. The study found that liver cancer rates per 100,000 males among cigarette smokers to nonsnmokers, in a major urban U.S. city, ...

**Statistics**

What does p-hat mean

**Statistics**

If a mother has three bananas, two pears, and two oranges, in how many different ways can she give the fruit to her daughter in one week, one piece of fruit per day?

**statistics**

In the population, the average IQ is μ = 100 with a standard deviation of σ = 15. A team of scientists wants to test a new medication to see if it has a positive effect on intelligence. A sample of n = 10 participants who have taken the medication has a mean of M = ...

**statistics**

I need help, I am trying to figure out the critical value of my homework and I am having a great deal of trouble. if z= 1.69 p = .0455 What is the critical value(s) , is/are z =?

**statistics**

The mean cost of domestic airfares in the United states rose to an all-time high of $385 per ticket

**Business Statistics**

The following tables shows the hourly wages of all workers in a certain hospital. Determine the pearsonian coefficient of skewness (population data). Hourly wages frequency 90-99 5 100-109 9 110-119 5 120-129 7 130-139 5 140-149 3 My answers: mean = 116.56 s = 15.72 But i don'...

**statistics**

A coin mint has a specification that a particular coin has a mean weight of 2.5 g. A sample of 39 coins was collected. Those coins have a mean weight of 2.49491 g and a standard deviation of 0.01372 g. Use a 0.05 significance level to test the claim that this sample is from a ...

**statistics**

Suppose IQ scores were obtained from randomly selected twins. For 20 such pairs of people, the linear correlation coefficient is 0.876 and the regression line is y-hat = 11,76 + 0.89x, where x represents the IQ score of the twin born second. Also,the 20x values have a mean of ...

**math/statistics**

The data show the time intervals after an eruption (to the next eruption) of a certain geyser. Find the regression equation,letting the first variable be the independent (x) variable. Find the best predicated time of the interval after an eruption given that the current ...

**Statistics**

Identify the type I error and type II error that corresponds to the given hypothesis. The proportion of settled medical malpractice suits is 0.28 I have been working on this one for 3 hours and am doing something wrong, Please help!!

**statistics**

For an IQ test, we know the population mean = 100 and the standard deviation =16. We are interested in creating the sampling distribution when N = 64. (a) What does that sampling distribution of means show? (b) What is the shape of the distribution of IQ means and the mean of ...

**Statistics**

If bird flu mortality in one sample of 100 is 20% and in another sample of 100 it is 30%. Is the difference in mortality rate is significant? Solve for the statistic value of Z at probability alpha level of 0.05. Please show your solution.

**statistics**

A survey found that women's heights are normally distributed with mean 62.4 in and standard deviation 2.8 in. The survey also found that men's heights are normally distributed with a mean of 68.9 in. and standard deviation 2.8. Complete parts a through c below. a. Most of the ...

**Statistics/Probability**

A certain brand of candies have a mean weigh of 0.8576 g and a standard deviation of 0.0523. A sample of these candies came from a package containing 447 candies,and the package label stated the net weight is 381.3 g. (If every package has 447 candies, the mean weight of the ...