Data Science For Business And Decision Making 1st Edition Luiz Paulo Favero, Patricia Belfiore - Solutions

A gas and oil company wants to understand how petroleum refining processes and the type of petroleum impact gasoline quality parameters, more specifically its octane rating. In order to do that, an
A steel company wants to know how the factors “Type of iron ore” and “Type of converter” affect the properties of steel, more specifically the Brinell hardness (BH), measured in kgf/mm2 . In
An aerospace company manufactures civilian and military helicopters at its three factories. Table 21.1 shows its monthly helicopter production in the last 12 months, in each factory. Check and see if
For a transportation problem with 3 suppliers with capacities for 50, 30, and 20 units, respectively, and 3 consumers with demand for 50, 10, and 40 units, respectively, determine the initial FBS
Same for the following problem: minz ¼ 3x12 + 2x13 + 5x14 + 4x24 + 4x34 + 4x35 + 6x36 + 5x46 + 4x56 + 4x57 + 5x67 + 3x68 + 3x78 s:t: x12 + x13 + x14 ¼ 1 x68 + x78 ¼ 1 x12 x24 ¼ 0 x13 x34 x35
Same for this problem: maxz ¼ x47 + x57 + x67 s:t: x47 + x57 + x67 x12 x13 x14 ¼ 0 x12 x24 x25 ¼ 0 x13 x34 x36 ¼ 0 x14 + x24 + x34 x45 x46 x47 ¼ 0 x25 + x45 x57 ¼ 0 x36 + x46 x67 ¼
Consider the following problem: minz ¼ 4x11 + 8x12 + 6x13 + 4x14 + 9x21 + 8x22 + 8x23 + 5x24 + 6x31 + 7x32 + 5x33 + 9x34 s:t: x11 + x12 + x13 + x14 ¼ 70 x21 + x22 + x23 + x24 ¼ 80 x31 + x32 + x33
Draw a network that presents the following sets of nodes and arcs: N ¼ f g 1, 2, 3, 4, 5, 6, 7, 8 A ¼ fð Þ 1, 3 , 1, 4 ð Þ, 2, 1 ð Þ, 2, 4 ð Þ, 3, 4 ð Þ, 3, 5 ð Þ, 4, 6 ð Þ, 5, 7 ð
Using the following network, determine:a) A tree.b) A spanning tree. 2 4 5 6
Same for the following network: 3 2 5
Consider the following network: Determine:a) The set of nodes of the network (N).b) The set of arcs of the network (A).c) If a network is directed or undirected.d) A directed path.e) An undirected
Among the logistics performance indicators, we can use the transportation costs as a percentage of the sales, which gives us a general overview of the transportation costs within the company’s
The daily demand of computers at a certain company is random. It may be represented by a normal distribution with mean 625 and standard deviation 40. The daily production of the product is also a
Do the same for a variable with a binomial distribution with values P ¼.8 and n ¼100.
Do the same for a variable with a uniform distribution between 54 and 88.
Generate 1000 random numbers for a variable that has a normal distribution with mean 120 and standard deviation 34. Construct a line chart to see the evolution of the series of data generated, as
A group of 15 consumers evaluated their level of satisfaction (1—somewhat dissatisfied, 2—somewhat satisfied, and 3—very satisfied) with three different bank services. The results can be seen
Aiming to compare the average service times in two bank branches, data on 22 clients from each bank branch were collected, as shown in the table. Use the most suitable test, with a significance level
A group of 20 teenagers went on the Points Diet for 30 days. Check and see if there was weight loss after the diet. Assume that a ¼5%. Before After 58 56 67 62 72 65 88 841 77 72 67 68 75 76 69 62
A group of 60 readers evaluated three novels and, at the end, they chose one of the three options, as shown in the table. Test the null hypothesis that there is no difference in these readers’
A group of 20 consumers tasted two types of coffee (A and B). At the end, they chose one of the brands, as shown in the table. Test the null hypothesis that there is no difference in these
Which test is an alternative to the t-test for one sample when the data distribution does not follow a normal distribution?
What are the differences between the sign test and the Wilcoxon test for two paired samples?
What are the advantages and disadvantages of nonparametric tests?
In what situations are nonparametric tests applied?
An aerospace company produces civilian and military helicopters at its three factories. The tables show the monthly production of helicopters in the last 12 months at each factory. Check if there is
Thirty teenagers whose total cholesterol level is higher than what is advisable underwent treatment that consisted of a diet and physical activities. The tables show the levels of LDL cholesterol
We would like to compare the average waiting time before being seen by a doctor (in minutes) in two hospitals. In order to do that, we collected a sample with 20 patients from each hospital. The data
A fat-free yogurt manufacturer states that the number of calories in each cup is 60 cal. In order to check if this information is true, a random sample with 36 cups is collected; and we observed
The table shows the final grades of two students in nine subjects. Check and see if there is variance homogeneity between the students (a ¼5%). Student 1 6.4 5.8 6.9 5.4 7.3 8.2 6.1 5.5 6.0 Student
Test the normality of the temperature data listed (a ¼5%): 12.5 14.2 13.4 14.6 12.7 10.9 16.5 14.7 11.2 10.9 12.1 12.8 13.8 13.5 13.2 14.1 15.5 16.2 10.8 14.3 12.8 12.4 11.4 16.2 14.3 14.8 14.6 13.7
The monthly aircraft sales data throughout last year can be seen in the table below. Check and see if there is normality in the data. Consider a ¼5%. Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sept.
What are the main mean comparison tests? What are the assumptions of each test?
To test a single population mean, we can use z-test and Student’s t-test. In what cases must each one of them be applied?
What are the main parametric tests to verify the normality of the data? In what situations must we use each one of them? (4) What are the main parametric tests to verify the variance homogeneity
What are the advantages and disadvantages of parametric tests?
In what situations should parametric tests be applied and what are the assumptions of these tests?
Consider a municipality with 120,000 inhabitants. We would like to estimate the percentage of the population that lives in urban and rural areas. The sampling plan used divides the municipality into
The population of a certain municipality with 120,000 inhabitants is divided into five regions (North, South, Center, East, and West). The table shows the number of inhabitants per region. A random
We would like to estimate the illiteracy rate in a municipality with 4000 inhabitants who are 15 or over 15 years of age. Based on previous surveys, we can estimate that p^¼ 0:24. A random sample
The population of the city of Sao Paulo is divided into 96 districts. From this total, 24 districts will be randomly drawn and, for each one of them, a small sample of the population will be
In a production line, one batch with 1500 parts is produced every hour. From each batch, we randomly pick a sample with 125 units. In each sample unit, we inspect all the quality characteristics to
Assume that the population of the city of Youngstown (OH) is divided by educational level. Thus, for each level, a percentage of the population will be interviewed. What type of sampling should be
To verify if a part meets certain quality specification demands, from every batch with 150 parts produced, we randomly pick a unit and inspect all the quality characteristics. What type of sampling
What type of sampling is used in the EuroMillions Lottery?
What are the advantages and limitations of each sampling technique?
What is the difference between stratified and cluster sampling?
What are the differences between random and nonrandom sampling techniques? In what cases must they be used?
Consider a random variable X that follows Snedecor’s F distribution with n1¼4 and n2¼16 degrees of freedom, that is, XF4, 16. Determine:a) P(X>3)b) F4, 16 with a¼2.5%c) The x value such that
A random variable T follows Student’s t distribution with n¼20 degrees of freedom. Determine:a) Critical value tc such that P(tc3)b) P(T2)c) P(1.5t)¼0.025
Now, assume that X follows a chi-square distribution with n¼16 degrees of freedom. Determine:a) P(X>25)b) P(X32)c) P(25x)¼0.975
A random variable X has a chi-square distribution with n¼12 degrees of freedom. What is critical value xc such that P(X>xc)¼90%?
The time between clients’ arrivals in a restaurant follows an exponential distribution with a mean of 3 minutes. Determine:a) The probability of more than 3 clients arriving in 6 minutes;b) The
The arrival of patients in a lab follows an exponential distribution with an average rate of 1.8 clients per minute. Determine:a) The probability of the next client’s arrival taking more than 30
A certain type of device follows an exponential distribution with a mean lifetime of 180 hours. Determine:a) The probability of the device lasting more than 220 hours;b) The probability of the device
The time until a certain electronic device fails follows an exponential distribution with a failure rate per hour of 0.028. Determine the probability of a device chosen randomly remaining operational
When tossing 40 balanced coins, determine the following probabilities:a) Of getting exactly 22 heads.b) Of getting more than 25 heads. Solve this exercise by approximating the distribution through a
Assume that a certain random variable X follows a normal distribution with m¼8 and s2 ¼36. Determine the following probabilities:a) P(X12)b) P(X2)d) P(6zc)¼80%.
Assume that, in a certain hospital, 3 patients undergo stomach surgery daily, following a Poisson distribution. Calculate the probability of 28 patients undergoing surgery next week (7 business days)
The probability of a player scoring a penalty is 95%. Determine the probability of the player having to take a penalty kick 33 times to score 30 goals, besides the mean of penalty kicks.
A telemarketing salesman sells one product every 8 customers he contacts. The salesman prepares a list of customers. Determine the probability of the first product being sold in the fifth call, in
The probability of a student solving a certain problem is 12%. If 10 students are selected randomly, what is the probability of exactly one of them being successful?
In a shoe production line, the probability of a defective item being produced is 2%. For a batch with 150 items, determine the probability of a maximum of two items being defective. Also determine
What is the difference between arrangements, combinations, and permutations?
Two dice are rolled simultaneously. Determine:a. The sample space.b. What is the probability of both numbers being even?c. What is the probability of the sum of the numbers being 10?d. What is the
A number between 1 and 30 is chosen randomly. We would like you to:a. Define the sample space.b. What is the probability of this number being divisible by 3?c. What is the probability of this number
A production batch contains 240 parts and 12 of them are defective. One part is drawn randomly. What is the probability of this part being defective?
In a deck of cards with 52 cards, determine:a. The probability of a card of hearts being drawn;b. The probability of a queen being drawn;c. The probability of a face card (jack, queen, or king) being
Two soccer teams will play overtime until the Golden Goal is scored. Define the sample space.
The files Brazilian_Supermarkets.sav and Brazilian_Supermarkets.dta show revenue data and the number of stores of the 20 largest Brazilian supermarket chains in a given year (source: ABRAS -
The files Students_Evaluation.sav and Students_Evaluation.dta show the grades, from 0 to 10, of 100 students from a public university in relation to the following subjects: Operational Research,
The files Motivation_Companies.sav and Motivation_Companies.dta show a database with the variables Company and Level of Motivation (Motivation), obtained through a survey carried out with 250
Aiming at identifying the behavior of customers who are in default regarding their payments, a survey with information on the age and level of default of the respondents was carried out. The
What are the main summary measures to represent the data behavior between two quantitative variables? Describe each one of them.
What are the differences between the chi-square statistic (w2 ), Phi coefficient, the contingency coefficient (C), Cramer’s V coefficient, and Spearman’s coefficient?
In what situations should we use contingency tables?
And to represent the behavior of two quantitative variables?
Which descriptive statistics can be used (and in which situations) to represent the behavior of two qualitative variables simultaneously?
Aiming to determine the standards of the investments made in hospitals in Sao Paulo (US$ millions), a state government agency collected data regarding 15 hospitals, as shown in Table 3.7.We would
A financial analyst wants to compare the price of two stocks throughout the previous month. The data are listed in Table 3.6.Carry out a comparative analysis of the price of both stocks based on:a)
In order to improve the quality of its services, a retail company collected the average service time, in seconds, of 250 employees. The data were grouped into classes, with their respective absolute
A passenger collected the average travel times (in minutes) of a bus in the district of Vila Mariana, on the Jabaquara route, for 120 days (Table 3.4). We would like you to:a) Calculate the
In a certain bank branch, we collected the average service time (in minutes) from a sample with 50 customers regarding three types of services. The data can be found in files Services.xls,
To preserve ac¸aı´, it is necessary to carry out several procedures, such as, whitening, pasteurization, freezing, and dehydration. The files Dehydration.xls, Dehydration.sav, and Dehydration.dta
At an electrical appliances factory, in the door component production phase, the quality inspector verifies the total number of parts rejected per type of defect (lack of alignment, scratches,
A survey on patients’ health was carried out and information regarding the weight of 50 patients was collected (Table 3.2). Build the frequency distribution table for this problem. TABLE 3.2
Table 3.1 shows the number of vehicles sold by a dealership in the last 30 days. Construct a frequency distribution table for these data. TABLE 3.1 Number of Vehicles Sold 7 5 9 11 10 8 9 9 8 10 8 5
What are the most suitable charts to represent qualitative data?
In the case of bar charts and scatter plots, what kind of data should be used?
What is the best chart to check the position, skewness and discrepancy among the data?
What is the difference between Pearson’s first and second coefficients used as measures of skewness in a distribution?
Describe each one of the measures of dispersion or variability.
How can we verify the existence of outliers in a certain variable?
What are the limitations of only using measures of central tendency in the study of a certain variable?
What statistics can be used (and in which situations) to represent the behavior of a single quantitative or qualitative variable?
A researcher wishes to study the impact of physical aptitude on the improvement of productivity in an organization. How would you describe the binary variables to be included in this model, so that
Classify the variables below according to the following scales: nominal, ordinal, binary, discrete, or continuous.a. A company’s revenue.b. A performance rank: good, average, and bad.c. Time to
What is the difference between discrete and continuous variables?
What are scales of measurement and what are the main types of scales? What are the differences between them?
What is the difference between qualitative and quantitative variables?

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Data Science For Business And Decision Making 1st Edition Luiz Paulo Favero, Patricia Belfiore - Solutions

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