Statistics BTM8104 Week 2
This section explains the process and purpose of creating graphs and charts that present statistical information in a visual manner. Histograms, bar graphs, boxplots, pie charts, stem and leaf charts, frequency tables, and line charts will be examined. You will also learn and calculate important descriptive statistics such as the measures of central tendency and dispersion, quartiles, and how to identify the shape of distributions. At the end of this section, you should be able to present data visually through the use of charts, graphs and tables, as well as calculate and interpret the mean, median, mode, range, standard deviation, and quartiles for given data. You will also begin to utilize statistical software programs to perform important statistical procedures.
Assignment 2 Exercises – Graphs and Descriptive Statistics
BTM8104 Week 2
Chapter One
Determine whether the evaluated group is a population or a sample
Based on a randomly selected group of 500 patients with high cholesterol, it was found that 67% have heart disease. Is this a population or a sample; explain your answer.
The randomly selected group of 500 patients is a considered a sample. It is considered a group as it was taken from a larger group of patients with high cholesterol, which formed the overall population.
An investigation of 150 randomly selected local restaurants concluded that 42% of local restaurants have serious health code violations. Is this a population or a sample; explain your answer.
The randomly selected group of 150 local restaurants is a sample. This is considered a sample as it was taken from a larger population of local restaurants, and selected to represent that larger restaurant population.
Determine whether the given value is a statistic or a parameter.
A researcher determines that 42.7% of all downtown office buildings have ventilation problems. Is this a statistic or a parameter; explain your answer.
This is considered a parameter. A parameter is an unknown fixed number that describes an already determined quality of a population. The population in this case is downtown office buildings and the conclusion from the study is a parameter of the population.
After taking the first exam, 15 of the students dropped the class. Is this a statistic or a parameter; explain your answer.
This is considered a statistic. A statistic is a known number which is calculated from a sample and is used to determine parameter qualities for a larger population. The class is the sample for a population of all classes that took the exam, resulting in the statistic.
Identify the type of sampling used.
A tax auditor selects every 1000th income tax return that is received. What type of sample is this and why?
This is considered systematic sampling. Systematic sampling is where every Kth entry of a population is selected to constitute the sample. In this case, the interval represented by K is every 1000th income tax returns.
The name of each contestant is written on a separate card, and the cards are placed in a bag with three names being picked from the bag. What type of sample is this and why?
This is considered simple random sampling. Simple random sampling is where a sample is picked from the population by randomly selecting the entries or items from the population blindly. The person doing the sampling is not allowed to see the entry/item he/she is selecting.
Is the study experimental or observation and why?
A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.
This is considered an observation study. An observation study seeks to find the relationship between changes or differences that exist. In this example, it can be inferred that the researcher observed a relationship between the candidate’s undecided poll prospects and the lead the candidate has at this point in time.
Select the study that is most appropriate and EXPLAIN WHY it is most appropriate for the study.
A+ - Thank you!
Thanks for the positive feedback!