
Concept explainers
What are
a.

Define descriptive statistics
Explanation of Solution
Descriptive statistics:
If a sample is taken and some statistics or sample characteristics are obtained from the sample but no inference is made about the entire population by using this information which is available from the sample, then it is termed as descriptive statistics.
The descriptive measures have three key characteristics:
- Center
- Variability
- Shape
Measures of Center:
An individual value that attempts to describe an observation by identifying the central position of the sample data is known as measures of central tendency.
Characteristics of center:
- Mean
- Median
- Mode
- Midrange
- Geometric mean
- Trimmed mean
Variability:
The measures of variability calculate the amount of spread or deviation in the observations. If the values corresponding to the variability are high, it means that the values in the data set are spread out wide.
Characteristics of the variability:
- Range
- Sample variance
- Sample standard deviation
- Coefficient of variation
- Mean absolute deviation
Measures of shape:
The shape of the data can be predicted by having the view on the shape of the graphs like histogram or boxplots or by comparing the value of the mean and median.
b.

Explain how the descriptive measures differ from the visual displays of data.
Explanation of Solution
The statistical method helps to organize, explore and summarize the raw data in to useful information. The methods of statistics may be in visual form (Charts or graphs) or numerical form (Statistics or tables). In statistics, data visualization deals with the charts and graphs. A surveyor uses the visual form of data for clear explanation. In common, it is a practice to continue an analysis by examining graphical displays of the data set. The method of visual representation makes the people to understand the data easily.
However, the visualization has the clear logical ideas but it also needs some descriptive reports about the data. It is hard to visualize the raw data into graphical form without any descriptive measures. In order to analyze the data set, descriptive measure will give clear explanation along with graphical representation.
Want to see more full solutions like this?
Chapter 4 Solutions
APPLIED STAT.IN BUS.+ECONOMICS
Additional Math Textbook Solutions
Graphical Approach To College Algebra
Finite Mathematics for Business, Economics, Life Sciences and Social Sciences
Elementary Statistics: Picturing the World (7th Edition)
Introductory Statistics
Elementary & Intermediate Algebra
- You find out that the dietary scale you use each day is off by a factor of 2 ounces (over — at least that’s what you say!). The margin of error for your scale was plus or minus 0.5 ounces before you found this out. What’s the margin of error now?arrow_forwardSuppose that Sue and Bill each make a confidence interval out of the same data set, but Sue wants a confidence level of 80 percent compared to Bill’s 90 percent. How do their margins of error compare?arrow_forwardSuppose that you conduct a study twice, and the second time you use four times as many people as you did the first time. How does the change affect your margin of error? (Assume the other components remain constant.)arrow_forward
- Out of a sample of 200 babysitters, 70 percent are girls, and 30 percent are guys. What’s the margin of error for the percentage of female babysitters? Assume 95 percent confidence.What’s the margin of error for the percentage of male babysitters? Assume 95 percent confidence.arrow_forwardYou sample 100 fish in Pond A at the fish hatchery and find that they average 5.5 inches with a standard deviation of 1 inch. Your sample of 100 fish from Pond B has the same mean, but the standard deviation is 2 inches. How do the margins of error compare? (Assume the confidence levels are the same.)arrow_forwardA survey of 1,000 dental patients produces 450 people who floss their teeth adequately. What’s the margin of error for this result? Assume 90 percent confidence.arrow_forward
- The annual aggregate claim amount of an insurer follows a compound Poisson distribution with parameter 1,000. Individual claim amounts follow a Gamma distribution with shape parameter a = 750 and rate parameter λ = 0.25. 1. Generate 20,000 simulated aggregate claim values for the insurer, using a random number generator seed of 955.Display the first five simulated claim values in your answer script using the R function head(). 2. Plot the empirical density function of the simulated aggregate claim values from Question 1, setting the x-axis range from 2,600,000 to 3,300,000 and the y-axis range from 0 to 0.0000045. 3. Suggest a suitable distribution, including its parameters, that approximates the simulated aggregate claim values from Question 1. 4. Generate 20,000 values from your suggested distribution in Question 3 using a random number generator seed of 955. Use the R function head() to display the first five generated values in your answer script. 5. Plot the empirical density…arrow_forwardFind binomial probability if: x = 8, n = 10, p = 0.7 x= 3, n=5, p = 0.3 x = 4, n=7, p = 0.6 Quality Control: A factory produces light bulbs with a 2% defect rate. If a random sample of 20 bulbs is tested, what is the probability that exactly 2 bulbs are defective? (hint: p=2% or 0.02; x =2, n=20; use the same logic for the following problems) Marketing Campaign: A marketing company sends out 1,000 promotional emails. The probability of any email being opened is 0.15. What is the probability that exactly 150 emails will be opened? (hint: total emails or n=1000, x =150) Customer Satisfaction: A survey shows that 70% of customers are satisfied with a new product. Out of 10 randomly selected customers, what is the probability that at least 8 are satisfied? (hint: One of the keyword in this question is “at least 8”, it is not “exactly 8”, the correct formula for this should be = 1- (binom.dist(7, 10, 0.7, TRUE)). The part in the princess will give you the probability of seven and less than…arrow_forwardplease answer these questionsarrow_forward
- Selon une économiste d’une société financière, les dépenses moyennes pour « meubles et appareils de maison » ont été moins importantes pour les ménages de la région de Montréal, que celles de la région de Québec. Un échantillon aléatoire de 14 ménages pour la région de Montréal et de 16 ménages pour la région Québec est tiré et donne les données suivantes, en ce qui a trait aux dépenses pour ce secteur d’activité économique. On suppose que les données de chaque population sont distribuées selon une loi normale. Nous sommes intéressé à connaitre si les variances des populations sont égales.a) Faites le test d’hypothèse sur deux variances approprié au seuil de signification de 1 %. Inclure les informations suivantes : i. Hypothèse / Identification des populationsii. Valeur(s) critique(s) de Fiii. Règle de décisioniv. Valeur du rapport Fv. Décision et conclusion b) A partir des résultats obtenus en a), est-ce que l’hypothèse d’égalité des variances pour cette…arrow_forwardAccording to an economist from a financial company, the average expenditures on "furniture and household appliances" have been lower for households in the Montreal area than those in the Quebec region. A random sample of 14 households from the Montreal region and 16 households from the Quebec region was taken, providing the following data regarding expenditures in this economic sector. It is assumed that the data from each population are distributed normally. We are interested in knowing if the variances of the populations are equal. a) Perform the appropriate hypothesis test on two variances at a significance level of 1%. Include the following information: i. Hypothesis / Identification of populations ii. Critical F-value(s) iii. Decision rule iv. F-ratio value v. Decision and conclusion b) Based on the results obtained in a), is the hypothesis of equal variances for this socio-economic characteristic measured in these two populations upheld? c) Based on the results obtained in a),…arrow_forwardA major company in the Montreal area, offering a range of engineering services from project preparation to construction execution, and industrial project management, wants to ensure that the individuals who are responsible for project cost estimation and bid preparation demonstrate a certain uniformity in their estimates. The head of civil engineering and municipal services decided to structure an experimental plan to detect if there could be significant differences in project evaluation. Seven projects were selected, each of which had to be evaluated by each of the two estimators, with the order of the projects submitted being random. The obtained estimates are presented in the table below. a) Complete the table above by calculating: i. The differences (A-B) ii. The sum of the differences iii. The mean of the differences iv. The standard deviation of the differences b) What is the value of the t-statistic? c) What is the critical t-value for this test at a significance level of 1%?…arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt


