BANA 1 Final (Winofsky)

Fowle Marketing Research, Inc., bases charges to a client on the assumption that telephone surveys can be completed in a mean time of 16 minutes or less. If a longer mean survey time is necessary, a premium rate is charged. A sample of 35 surveys from a particular client provided the survey times shown in the file named Fowle. Based upon past studies, the population standard deviation is assumed known with σ = 6 minutes. Fowle would like to test whether the premium rate is justified for this customer. What is the p-value associated with this hypothesis test? (Round your answer to three decimal places.)

#1. sample mean =AVERAGE(data) #2. =(AVERAGE-16) #3. std.er=6/sqrt(35) #4. test stat=#2/#3 #5 =NORM.S.DIST(#4,1) p-value =(1-#5)

The average home in the U.S. is expected to cost $240,000. A random sample of 54 homes sold this month showed an average price of $232,000. Assume that you have access to this data. We are interested in determining if the cost of the average home has decreased this month. If the test statistic is -1.63, what is the p-value? (Round your answer to three decimal places.)

*one tail test! -1.63 54 p-value=T.DIST(-1.63,54-1,1)

In a local university, 65% of the students live in the dormitories. A random sample of 73 students is selected for a particular study. We know that the standard error of the proportion is 0.0558. Find the probability that the sample proportion (the proportion living in the dormitories) is between 64% and 66%. (Round your answer to three decimal places.)

.66-.65= .01 .64-.65= -.01 std.er=.0558 z-value=.01 and -.01/std.er =NORM.S.DIST(z-value,1) Difference between each

Using the attached Student Data, determine the median of Sleep. Enter your answer rounded to one decimal places.

1. =MED(Sleep column)

Decide whether each situation demonstrates a discrete or continuous random variable.

1. The number of faculty members who entered Lindner yesterday. Discrete 2. Your weight in kilograms. Continuous 3. The number of times that you have signed into Canvas today. Discrete 4. The number of students who attend a recitation session. Discrete 5. The amount of time yesterday each student studied for this exam. Continuous

A seven-year medical research study reported that women whose mothers took the drug diethylstilbestrol (DES) during pregnancy were twice as likely to develop tissue abnormalities that might lead to cancer as were women whose mothers did not take the drug. This study compared two populations. What were the populations? (Select all that apply.)

1. all women whose mothers did not take the drug DES during pregnancy 2. all women whose mothers took the drug DES during pregnancy

If you created a bar chart showing the frequency of Birth Month using the attached Student Data, the month with the lowest bar would be

1. highlight data, insert Pivot table 2. birth month - rows 3. birth month values

Use the attached Student Data and an Excel PivotTable to determine the number of students who are Finance majors and do not wear contacts or glasses.

1. highlight data, insert pivot table 2. put major in rows, glasses in columns, either variable in value

Use the attached Student Data and an Excel PivotTable to determine the total number of Facebook Friends Marketing students have.

1. highlight data, insert pivot table 2. major in rows 3. facebook friends in values (sum) 4. look at marketing

The following represents the probability distribution for the daily demand of computers at a local store. (data) What is the expected daily demand? (Round your answer to two decimal places.)

1. put data in excel 2. =demand*probability for each row 3. =sum total values

A population has a standard deviation of 16. A random sample of 124 items from this population is selected. The sample mean is determined to be 325. What is the margin of error at 95% confidence? (Round your answer to three decimals.)

1. put data in spreadsheet 2.std.er=16/sqrrt(124) 3. .95 4. 1-.95 5. Z=Norm.s.inv(1-.05/2) 6. =*Std.er

A population has a standard deviation of 12. If a sample of size 47 is selected from this population, what is the probability that the sample mean will be within plus or minus two of the population mean? (Round your answer to three decimal places.)

1. put into excel 2.STD.ER=12/47 -2/STD.ER=z value 2/STD.ER=z value NORM.S.DIST(z value, 1) for each Difference between each

A psychologist developed a new test of adult intelligence. The test was administered to 20 individuals, and the following data were obtained. 124, 109, 141, 134, 127, 111, 115, 137, 129, 125, 108, 113, 154, 164, 142, 115, 135, 132, 128, 128 If you construct a stem-and-leaf display for the data, using a leaf unit of 1, the third stem would be

1. stem is first two digits 2. smallest number is 108 so first two digits is 10 3. second stem is 11 4. third stem is 12

The sum of the probabilities of two complementary events is

1.0

What will the sum of the percent frequencies for all classes always equal?

100

The student body of a large university consists of 55% Arts & Science students. A random sample of 10 students is selected. What is the expected number of Arts & Science students selected? (Round your answer to one decimal place.)

=.55*10

The assembly time for a product is uniformly distributed between 10 to 20 minutes. What is the probability that the assembly will take less than 12 minutes? (Round your answer to two decimal places.)

=12-10 =2*.1 =.2

The response to a question has three alternatives: A, B, and C. A sample of 120 responses provides 56 A, 26 B and 38 C responses. What is the relative frequency of C? Round your answer to two decimal places.

=36/120

An experiment consists of three steps. There are nine possible results on the first step, thirteen possible results on the second step, and fifteen possible results on the third step. The total number of experimental outcomes is

=9*13*15

Using the attached Student Data, determine the average of Height. Enter your answer rounded to one decimal place.

=AVERAGE(Height column)

The file HongKongMeals contains the costs for a sample of 42 recent meals for two in Hong Kong midrange restaurants. What is the 96% confidence interval estimate of the population mean cost in dollars for a mid-range meal for two in Hong Kong? (Round your answers to the nearest cent.)

=AVG(column) =STDEV.S(column) =COUNT(column) std.er=STDEV.S/sqrt(count) =1-.96=.04 =T.INV(1-.04/2,Count-1) margin of error=^*std.er =mean-margin of error =mean+margin of error

Suppose that, from a population of fifty-eight bank accounts, we want to take a random sample of four accounts in order to learn about the population. How many different random samples of four accounts are possible?

=COMBIN(58,4)

Intensive care units (ICUs) generally treat the sickest patients in a hospital. ICUs are often the most expensive department in a hospital because of the specialized equipment and extensive training required to be an ICU doctor or nurse. Therefore, it is important to use ICUs as efficiently as possible in a hospital. Suppose that a large-scale study of elderly ICU patients shows that the average length of stay in the ICU is five days. Assume that this length of stay in the ICU has an exponential distribution. What is the probability that the length of stay in the ICU is three days or less? (Round your answer to four decimal places.)

=EXPON.DIST(3,1/5,1)

Axline Computers manufactures personal computers at two plants, one in Texas and the other in Hawaii. The Texas plant has 35 employees; the Hawaii plant has 25. A random sample of 10 employees is to be asked to fill out a benefits questionnaire. What is the probability that 5 of the employees in the sample work at the plant in Hawaii? (Round your answers to three decimal places.)

=HYPGEOM.DIST(5, 10, 25, 60, 0)

Compute the probability that z, a standard normal variable, is less than or equal to 1.4. (Round your answer to 4 decimal places.)

=NORM.S.DIST(1.4, 1)

Given that z is a standard normal random variable, find z if the area to the left of z is 0.2266. (Round your answers to 3 decimal places. .)

=NORM.S.INV(.2266)

Using the new Student Data, determine the 60th percentile of Facebook Friends. Enter your answer rounded to one decimal place.

=PERCENTILE.EXC(column, percentile) =PERCENTILE.EXC(Facebook column, .6)

A life insurance company has determined that each week an average of eleven claims is filed in its Nashville branch. What is the probability that during the next week eleven claims or less will be filed? (Assume that the arrival of claims can be described by a Poisson distribution and round your answer to three decimal places.)

=POISSON.DIST(11,11,1)

Using the attached Student Data, determine the 3rd quartile of Facebook Friends. Enter your answer rounded to one decimal places.

=QUARTILE.EXC(Facebook column, 3)

Using the attached Student Data, determine the skewness of Facebook Friends in this sample. Enter your answer rounded to one decimal place. Consider this data a sample not a population.

=SKEW(Facebook column)

Males in the Netherlands are the tallest, on average, in the world with an average height of 183 centimeters (cm).† Assume that the height of men in the Netherlands is normally distributed with a mean of 183 cm and standard deviation of 10.5 cm. What is the probability that a Dutch male is between 173 and 193 cm? (Round your answer to three decimal places.)

A) 173 -> =NORM.DIST(173, 183, 10.5, 1) B) 193 -> =NORM.DIST(193, 183, 10.5, 1) =B-A

Assume you have applied for two jobs Job A and Job B. The probability that you get an offer for only Job A is 0.24. The probability of being offered only Job B is 0.16. The probability of getting at least one of the jobs is 0.34. What is the probability that you will be offered both jobs? (Round your answer to two decimal places.)

A=.24 B=.16 (I) Intersection=A*B Union=A+B-I =.24+.16-.36

If A and B are independent events with P(A) = 0.25 and P(B) = 0.17, then P(A union B) =(Round your answer to two decimal places.)

A=.25 B=.17 (I) Intersection=A*B Union=A+B-I

According to a 2018 survey by Bankrate.com, 20% of adults in the United States save nothing for retirement (CNBC website). Suppose that twenty-one adults in the United States are selected randomly. What is the probability that more than five of the selected adults save nothing for retirement? (Round your answer to three decimal places.)

A=BINOM.DIST(5,21,.2,1) =1-A

The average manufacturing work week in metropolitan Chattanooga was 40.1 hours last year. It is believed that the contracting economy has led to a decrease in the average work week. To test the validity of this belief, the hypotheses are

H₀: the population mean is greater than or equal to 40.1; Hᴀ: the population mean is less than 40.1

As the sample size becomes larger, the sampling distribution of the sample mean approaches a(n)

Normal distribution

A simple random sample of 85 items resulted in a sample mean of 90. The population standard deviation is 𝜎 = 5.Compute the 95% confidence interval for the population mean. (Round your answers to two decimal places.)

Std.er=5/sqrt(85) Z=NORM.S.INV(1-.05/2) M=Z*STD.ER =90+M =90-M

If a hypothesis test leads to the rejection of the null hypothesis,

a Type I error may have been committed

A box plot is a graphical representation of data that is based on

a five number summary

In cluster sampling,

all elements within the randomly selected clusters form the sample.

The average home in the U.S. is expected to cost $244,000. A random sample of 67 homes sold this month showed an average price of $225,000 with a sample standard deviation $39,000. We are interested in determining if the cost of the average home has decreased this month. What is the value of the test statistic? (Round your answer to three decimal places.)

average=244,000 sample mean=225,000 sample stdev=39,000 sample size=67 std.er=stdev/sqrt(67) =mean-average test statistic=^/std.er

If the level of significance of a hypothesis test is raised from 0.025 to 0.05, the probability of a Type II error will

decrease

For a given level of Type I error, if we want to decrease the level of Type II error, the sample size must

increase

The probability that a continuous random variable takes any specific value

is equal to zero

The intersection of two mutually exclusive events

must always be equal to 0.

Consider the attached Student Data. Glasses is an example of a variable that uses the

nominal scale

A random sample of 100 people was taken. Eighty-four of the people in the sample favored Candidate A. We are interested in determining whether the proportion of the population in favor of Candidate A is significantly more than 78%. We know that the p-value is 0.0738. At the 0.05 level of significance, it can be concluded that the proportion of the population in favor of candidate A is

not significantly greater than 78%.

For a sample of retired teachers, several health factors are collected and compared for teachers who worked in older schools with asbestos issues and for teachers who worked in newer schools without asbestos issues This study would be considered

observational

The purpose of statistical inference is to provide information about the

population based upon information contained in the sample.

The key difference between the binomial and hypergeometric distributions is that, with the hypergeometric distribution, the

probability of success changes from trial to trial

Consider the attached Student Data. Facebook Friends is an example of a variable that uses the

ratio scale

A graphical presentation of the relationship between two variables is

scatter diagram

To decrease the margin of error, the sample size

should increase

One hundred graduating LCB students are randomly selected to participate in a survey. The survey asks many questions including whether the students plan to attend graduate school. LCB will use this data to highlight the percentage of graduating LCB students who plan to attend graduate school. Using the sample percentage to estimate the percentage of graduating LCB students who plan to attend graduate school is an example of

statistical inference

The average home in the U.S. is expected to cost $240,000. A random sample of homes sold this month showed an average price of $232,000. We are interested in determining if the cost of the average home has decreased this month. If the p-value associated with the test statistic is less than .001, our conclusion would be

the cost of the average house is less than $240,000.

Which of the following is the interquartile range?

the difference between the third quartile and the first quartile

In hypothesis testing, the tentative assumption about the population parameter is

the null hypothesis

Bayes' theorem is used to compute

the posterior probabilities

In computing the standard error of the mean, the finite population correction factor is used when

the sample size compared to the population size is greater than 5%

Since a sample is a subset of the population, the sample mean _____ the mean of the population.

varies around