Devry MATH221 Statistics for Decision Making Week 1 Homework

Question 1The age of every fourth person entering a department store. The selected individuals would be considered a:

Statistic

Parameter

Population

Correct!

Sample

Question 2 In a survey of 1000 adults, 34% found they prefer charcoal to gas grills. The 1000 would be considered a:

Sample

Population

Parameter

Statistic

The article I selected is called “Selective immunoglobulin A deficiency in children with diabetes mellitus: Data from a medical center in Ukraine.” This article reports a study done in western Ukraine. The goal of the study was to estimate the prevalence of selective immunoglobulin A  deficiency (SIgAD) among children with type 1 diabetes mellitus (DM). (Selective IgA deficiency is an immune system condition in which you lack or don’t have enough immunoglobulin A (IgA), a protein that fights infection) (MayoClinic.org). According to this article, SIgAD is one of the most common primary immunodeficiencies, and its prevalence ranges from 1:300 to 1:3000 depending o the population.  SIgAD is diagnosed in children older than four years with serum IgA below 7mg/dL, with normal immunoglobulins G (IgG) and M(IgM) and other causes of hypogammaglobulinemia and T cells defects ruled out.  In addition, the article also reports that this deficiency is a heterogeneous condition with a multifactorial mechanism and its pathogenesis is not completely understood and typically is associated with defects in B cells failing to produce IgA and T cell abnormalities and cytokine abnormalities also may play a role on this deficiency.

Question 3Inferential statistics is when sample data is used to:

Influence a decision maker

Calculate a mean

Say something about the population

Determine when an event is most likely to occur

Question 4The milligrams of tar in 30 cigarettes would be considered:

Interval data

Ratio data

Ordinal data

Nominal data

Question 5If a data set included the color of cars in a parking lot, those data would be considered:

Quantitative data

Ratio data

Qualitative data

Interval data

Question 6The amount of fat in grams in 58 cookies would be considered:

Interval data

Nominal data

Ordinal data

Ratio data

Question 7Five statistics classes out of 20 are selected and all the students in the selected classes are interviewed. This sampling technique is called:

Cluster

Convenience

Stratified

Random

Question 8A personnel director at a large company would like to determine whether the company cafeteria is widely used by employees. She calls each employee and asks them whether they usually bring their own lunch, eat at the company cafeteria, or go out for lunch. This study design would be considered:

Survey

Experimental

Observational

Simulation

 

Question 9Which of the following would be the mean of this data set: 5, 28, 12, 56, 4, 2, 30, 21

17.06

16.50

18.24

19.75

Question 10Which of the following would be the standard deviation of this population data set: 67, 54, 30, 77, 92, 41, 75, 81

21.226

64.625

19.855

517.000

Question 11Which of the following would be the variance of this population data set: 3, 6, 8, 9, 4, 5, 7, 1, 9, 7, 15, 4, 3, 1

25.73

13.00

3.74

14.00

Question 12What is the relationship between variance and standard deviation?

Variance is double the standard deviation

Standard deviation is double the variance

Standard deviation is the square of the variance

Variance is the square of the standard deviation

Question 13If data set A has a larger standard deviation than data set B, what would be different about their distributions?

Data set A would have flatter distribution with more data in each tail

Data set A would have a larger mean

Data set A would have more data near the center of the distribution

Data set A would have most of its data to one side of the distribution

Question 14In a normally distributed data set a mean of 55 where 99.7% of the data fall between 47.5 and 62.5, what would be the standard deviation of that data set?

2.5

5.0

7.5

5.7

Question 15Which of the following data sets would you expect to have the highest mean?

Height of pit bulls (in inches)

Prices of used cars (in dollars)

Ages of kids in a preschool program (in years)

Speed of cars during a professional car race (in mph)

Question 16

Which data outcome of the number of customers in line would best support opening another cash register?

High mean with small standard deviation

Low mean with high standard deviation

High mean with high standard deviation

Low mean with small standard deviation

Question 17In manufacturing, convenience sampling could be used to determine if the machines are operating correctly. Which of the following best describes this type of sampling?

Products are put into groups and some are randomly selected from each group

Every 10th product in the line is selected

Products are put into groups and all are included from several randomly selected groups

Samples are randomly selected throughout the day

Question 18A graph shows a line connecting the tops of vertical bars with the number of data points on the y-axis and groups on the x-axis. This graphic is most likely to be:

A dot plot

A frequency histogram

A frequency polygon

A stem-leaf plot

Question 19Match the terms and their definitions

Vertical bar chart that shows frequency on the y-axis

A sample where the population is divided into groups and several groups are randomly selected from all from those selected groups are sampled

Collection of all counts that are of interest

A subset or part of a population

A sample where the population is divided into groups and several are randomly sampled form each group

Consists of attributes, labels, or nonnumerical entries

Question 20Match the terms and their definitions

The most frequent number appearing in a dataset

The average

The percentage of data that falls within 1, 2, or 3 standard deviations of the mean in a symmetrical, bell-shaped distribution

The square root of the variance

Show how far a particular data point is from the mean in terms of the number of standard deviations