true or false: control charts are a useful tool for tallying the number of defects.
In: Math
ou may need to use the appropriate appendix table or technology to answer this question.
A consumer product testing organization uses a survey of readers to obtain customer satisfaction ratings for the nation's largest supermarkets. Each survey respondent is asked to rate a specified supermarket based on a variety of factors such as: quality of products, selection, value, checkout efficiency, service, and store layout. An overall satisfaction score summarizes the rating for each respondent with 100 meaning the respondent is completely satisfied in terms of all factors. Suppose sample data representative of independent samples of two supermarkets' customers are shown below.
Supermarket 1 | Supermarket 2 |
---|---|
n1 = 270 |
n2 = 300 |
x1 = 82 |
x2 = 81 |
(a)
Formulate the null and alternative hypotheses to test whether there is a difference between the population mean customer satisfaction scores for the two retailers. (Let μ1 = the population mean satisfaction score for Supermarket 1's customers, and let μ2 = the population mean satisfaction score for Supermarket 2's customers. Enter != for ≠ as needed.)
H0:
Ha:
(b)
Assume that experience with the satisfaction rating scale indicates that a population standard deviation of 14 is a reasonable assumption for both retailers. Conduct the hypothesis test.
Calculate the test statistic. (Use
μ1 − μ2.
Round your answer to two decimal places.)
Report the p-value. (Round your answer to four decimal places.)
p-value =
At a 0.05 level of significance what is your conclusion?
Reject H0. There is not sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers.Reject H0. There is sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers. Do not reject H0. There is sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers.Do not reject H0. There is not sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers.
(c)
Which retailer, if either, appears to have the greater customer satisfaction?
Supermarket 1Supermarket 2 neither
Provide a 95% confidence interval for the difference between the population mean customer satisfaction scores for the two retailers. (Use
x1 − x2.
Round your answers to two decimal places.)
to
In: Math
There are eight different jobs in a printer queue. Each job has a distinct tag which is a string of three upper case letters.
The tags for the eight jobs are: { LPW, QKJ, CDP, USU, BBD, PST, LSA, RHR }
How many different ways are there to order the eight jobs in the queue so that job USU comes somewhere before CDP in the queue (although not necessarily immediately before) and CDP comes somewhere before BBD (again, not necessarily immediately before)?
In: Math
Congratulations you have almost completed biostatistics and have decided since you loved the class so much you want to be a research scientist after you graduate. After applying for several jobs you were able to get your dream job at USF and the only requirement is that you conduct research. Explain in detail the steps you need to take to plan a research project, ranging from planning the question to obtaining a result from a statistical model. Experimental Design and Biostatistics
In: Math
Overproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of illness such as gout, leukemia, or lymphoma.† Over a period of months, an adult male patient has taken fifteen blood tests for uric acid. The mean concentration was x = 5.35 mg/dl. The distribution of uric acid in healthy adult males can be assumed to be normal, with σ = 1.91 mg/dl.
(a) Find a 95% confidence interval for the population mean concentration of uric acid in this patient's blood. What is the margin of error? (Round your answers to two decimal places.) lower limit upper limit margin of error
(b) What conditions are necessary for your calculations? (Select all that apply.)
uniform distribution of uric acid
σ is known
normal distribution of uric acid
n is large
σ is unknown
(d) Find the sample size necessary for a 95% confidence level
with maximal margin of error E = 1.08 for the mean
concentration of uric acid in this patient's blood. (Round your
answer up to the nearest whole number.)
blood tests
In: Math
In a study where the capability of a gauge was measured by the weight of paper, the following measurements were obtained: 3.481 3.448 3.485 3.475 3.472 3.477 3.472 3.464 3.508 3.170 4.123 3.470 2.893 3.473 4.201 3.474 4.301 3.021 3.231 3.405
Part I Using R do the following(SHOW R CODE): 1. Draw an appropriately titled histogram. Interpret the graph. 2. Draw an appropriately titled boxplot. Interpret the graph. 3. Compute the five-number summary. 4. Find the interquartile range. 5. Find the mean 6. Find the standard deviation. 7. What would be the appropriate measures of center and dispersion?
Part 2 Assuming the above sample data is coming from a normal population, construct a 95% confidence interval for the population mean.
In: Math
For X ~ BIN(20, 0.6), find the following probabilities (PLEASE SHOW CLEAR WORK):
P(X = 14) =
P(X > 15) =
P(X < 9) =
In: Math
According to the British United Provident Association, a major health care provider in the U.K., snoring can be an indication of sleep apnea which can cause chronic illness if left untreated. In the United States, the National Sleep foundation reports that 36.8% of the 995 adults they surveyed snored. Of the respondents, 81.5% were over the age of 30, and 32% were both over the age of 30 and snorers.
A. What is the probability of snoring?
B. What percent of the respondent were 30 or younger and did not snore?
In: Math
You may need to use the appropriate technology to answer this question.
Home values tend to increase over time under normal conditions, but the recession of 2008 and 2009 has reportedly caused the sales price of existing homes to fall nationwide.† You would like to see if the data support this conclusion. The file HomePrices contains data on 30 existing home sales in 2006 and 40 existing home sales in 2009.
213,100 | 226,200 | 239,100 |
214,300 | 161,700 | 181,200 |
228,600 | 222,100 | 228,900 |
235,800 | 219,400 | 238,800 |
301,800 | 264,200 | 320,200 |
315,000 | 118,900 | 172,400 |
137,500 | 212,800 | 175,400 |
311,400 | 296,900 | 292,500 |
287,700 | 246,500 | 195,600 |
155,300 | 152,400 | 211,200 |
155,400 | 189,800 | 200,800 | 280,400 |
213,200 | 181,100 | 117,400 | 130,000 |
170,000 | 149,600 | 146,200 | 54,400 |
213,800 | 186,000 | 182,100 | 180,000 |
215,700 | 164,200 | 95,300 | 239,500 |
207,200 | 188,200 | 169,400 | 185,600 |
177,000 | 178,000 | 161,200 | 249,200 |
146,400 | 99,800 | 246,700 | 173,500 |
138,100 | 112,200 | 137,500 | 147,900 |
179,000 | 116,200 | 197,500 | 164,200 |
(a)
Provide a point estimate of the difference (in dollars) between the population mean prices for the two years. (Use year 2006 − year 2009. Round your answer to the nearest dollar.)
$
(b)
Develop a 99% confidence interval estimate of the difference (in dollars) between the resale prices of houses in 2006 and 2009. (Use year 2006 − year 2009. Round your answers to the nearest dollar.)
$ to $
(c)
Would you feel justified in concluding that resale prices of existing homes have declined from 2006 to 2009? Why or why not?
To answer this question, we need to conduct a hypothesis test.
State the null and alternative hypotheses. (Let μ1 = mean home price in 2006 and let μ2 = mean home price in 2009.)
H0:μ1 − μ2 > 0
Ha:μ1 − μ2 ≤ 0
H0:μ1 − μ2 ≤ 0
Ha:μ1 − μ2 > 0
H0:μ1 − μ2 ≠ 0
Ha:μ1 − μ2 = 0
H0:μ1 − μ2 = 0
Ha:μ1 − μ2 ≠ 0
H0:μ1 − μ2 ≤ 0
Ha:μ1 − μ2 = 0
Find the value of the test statistic. (Round your answer to three decimal places.)
Find the p-value. (Round your answer to four decimal places.)
p-value =
State your conclusion. (Use α = 0.01)
Do not reject H0. We can conclude that existing home prices have declined between 2006 and 2009.
Do not reject H0. We can not conclude that existing home prices have declined between 2006 and 2009.
Reject H0. We can conclude that existing home prices have declined between 2006 and 2009
.Reject H0. We can not conclude that existing home prices have declined between 2006 and 2009.
In: Math
Here are summary statistics for randomly selected weights of newborn girls: nequals220, x overbarequals30.3 hg, sequals6.3 hg. Construct a confidence interval estimate of the mean. Use a 99% confidence level. Are these results very different from the confidence interval 29.0 hgless thanmuless than31.8 hg with only 18 sample values, x overbarequals30.4 hg, and sequals2.1 hg? What is the confidence interval for the population mean mu? nothing hgless thanmuless than nothing hg (Round to one decimal place as needed.)
In: Math
What are distinctions between big data, applied math, (finance/ economics) and statistics?
In: Math
Consider the following table of data that was generated from randomly surveying 100 people and recording how much change (from coins) was in their pockets:
0.33 |
0.01 |
0.69 |
0.04 |
0.46 |
0.16 |
1.67 |
0.12 |
0.03 |
0.17 |
0.09 |
0.17 |
0.57 |
0.04 |
0.29 |
0.85 |
0.46 |
1.17 |
0.02 |
0.12 |
0.74 |
1.72 |
0.28 |
0.12 |
1.37 |
0.61 |
0.06 |
1.46 |
0.42 |
0.03 |
0.39 |
0.10 |
0.02 |
0.20 |
1.08 |
1.27 |
0.30 |
1.13 |
0.06 |
0.27 |
3.76 |
0.43 |
0.04 |
0.37 |
0.09 |
0.09 |
0.22 |
1.06 |
0.09 |
0.01 |
0.17 |
1.23 |
0.12 |
1.51 |
0.13 |
0.18 |
0.50 |
0.73 |
0.03 |
0.63 |
0.05 |
0.36 |
0.11 |
0.74 |
0.12 |
0.90 |
0.91 |
0.12 |
0.38 |
0.02 |
0.17 |
0.20 |
0.40 |
0.47 |
0.36 |
0.99 |
0.35 |
1.27 |
1.64 |
1.67 |
0.74 |
0.04 |
0.62 |
0.08 |
0.09 |
0.15 |
0.01 |
0.05 |
1.03 |
0.15 |
0.09 |
0.49 |
0.89 |
0.18 |
0.10 |
0.15 |
1.27 |
1.23 |
0.34 |
0.42 |
1. Construct a histogram of the empirical data. Use ten "bins".Hint: It may be helpful to construct ten "bins" over the interval [0,4]
2. Construct a histogram of the empirical data. Use 20 bins.
3. Describe the shape of each graph.
In: Math
The Consumer Reports National Research Center conducted a telephone survey of 2,000 adults to learn about the major economic concerns for the future. The survey results showed that 1,740 of the respondents think the future health of Social Security is a major economic concern.
If computing the confidence intervals manually, make sure to use at least three decimal digits for the critical values.
a. What is the point estimate of the population
proportion of adults who think the future health of Social Security
is a major economic concern?
b. At 90% confidence, what is the margin of
error (to 4 decimals)?
c. Develop a 90% confidence interval for the population proportion of adults who think the future health of Social Security is a major economic concern (to 3 decimals).
( , ) , ( , )
d. Develop a 95% confidence interval for this population proportion (to 3 decimals).
( , ) , ( , )
Video
The range for a set of data is estimated to be 24.
e. What is the planning value for the population standard deviation?
f. At 95% confidence, how large a sample would provide a margin of error of 3?
g. At 95% confidence, how large a sample would provide a margin of error of 2?
In: Math
The number of female customers arriving to a coffee shop follow a Poisson process with a mean rate of 3 per hour. The number of male customers arriving to the same coffee shop also follow a Poisson process with a mean rate of 6 per hour and their arrival is independent of the arrivals of female customers.
a) What is the probability that the next customer will arrive within 5 minutes?
b) What is the probability that exactly thee customers will arrive in the next 5 minutes?
c) What is the probability of exactly two male and exactly one female customer will arrive in the next 5 minutes?
d). Parts b) and c) ask for the probability of exactly three arrivals in the next 5 minutes. Are they identical? Explain why?
e) What is the probability of exactly five customers will arrive between 6 and 7 hours from now?
In: Math
Suppose a legislator is deciding whether they should put in the effort to draft a bill. The legislator only wants to do this if they are convinced that a majority of their consituents support the bill. The legislator runs a poll of 1,000 constituents, and will be convinced that a majority of their constituents support the bill if the lower bound of the 95% confidence interval for the probability that a constituent supports the bill is greater than 0.50. 550 out of the 1,000 constituents polled indicate support for the bill. Will the legislator put in the effort to draft the bill? (Possible answers are yes or no).
In: Math