Exam 1 (BUSI2311)

Slate is a daily magazine on the Web. Its business activities can be described by a number of variables. What is the level of measurement for each of the following variables? -The number of hits on their website on Saturday between 8:00 a.m. and 9:00 a.m. -The departments, such as food and drink, politics, foreign policy, sports, etc. -The number of weekly hits on the Sam's Club ad. -The number of years each employee has been employed with Slate.

- The number of hits on their web site on Saturday has a significant zero point and the ratio between two numbers meaningful. So they are ratio level of measurement. -The departments are different from each other but have no meaning other than identification. So they are nominal level of measurement. -The number of weekly hits on the Sam's Club ad has a significant zero point and the ratio between two numbers meaningful. So they are ratio level of measurement. -The number of years each employee has been employed has a significant zero point and the ratio between two numbers meaningful. So they are ratio level of measurement.

Explain the difference between a sample and a population.

A population is the entire group which you are studying. A sample is a subset taken from a population.

For the following situations, would you collect information using a sample or a population? Statistics 201 is a course taught at a university. Professor Rauch has taught nearly 1,500 students in the course over the past 5 years. You would like to know the average grade for the course based on all 1,500 students. As part of a research project, you need to report the average profit as a percentage of revenue for the #1-ranked corporation in the Fortune 500 for each of the last 10 years. You are looking forward to graduation and your first job as a salesperson for one of five large pharmaceutical corporations. Planning for your interviews, you will need to know about each company's mission, profitability, products, and markets. You are shopping for a new MP3 music player such as the Apple iPod. The manufacturers advertise the number of music tracks that can be stored in the memory. Usually, the advertisers assume relatively short, popular songs to estimate the number of tracks that can be stored. You, however, like Broadway musical tunes and they are much longer. You would like to estimate how many Broadway tunes will fit on your MP3 player.

A population is used because the professor likely has grades readily available from every student over the past 5 years. A population is employed because the information is easy to find and there are only 10 observations in the entire population. A population is used because the information is easy and relatively quick to collect for only five companies. A sample works because it is difficult to locate every musical and the length of every song.

A seven-member committee of students is formed to study environmental issues. What is the likelihood that any one of the seven is randomly chosen as the spokesperson?

Classical

You purchase a ticket for the Lotto Canada lottery. Over 5 million tickets were sold. What is the likelihood you will win the $1 million jackpot?

Classical

Explain the difference between a discrete and a continuous variable.

Discrete variables can assume only certain values, but continuous variables can assume any values within some range.

Exits along interstate highways were formerly numbered successively from the western or southern border of a state. However, the Department of Transportation has recently changed most of them to agree with the numbers on the mile markers along the highway. What level of measurement were data on the consecutive exit numbers? What level of measurement are data on the milepost numbers? The newer system provided information on the distance between exits.

One exit number is higher or lower than another, but the differences between them are not the same. So the exit number is ordinal level of measurement. The milepost number has a significant zero point and the ratio between two numbers meaningful. So they are ratio level of measurement. The newer system provided more information, namely the distance between exits.

Explain the difference between qualitative and quantitative variables.

Qualitative data is not numerical, whereas quantitative data is numerical

A poll solicits a large number of college undergraduates for information on the following variables: the name of their cell phone provider (AT&T, Verizon, and so on), the numbers of minutes used last month (200, 400, for example), and their satisfaction with the service (Terrible, Adequate, Excellent, and so forth). What is the level of measurement for each of these three variables? -The Cell phone provider -The number of minutes used -Satisfaction with the service

-Nominal -Ratio -Ordinal The cell phone providers are different from each other but have no meaning other than identification. So they are nominal level of measurement. The minutes used has a significant zero point and the ratio between two numbers meaningful. So they are ratio level of measurement. Satisfaction ratings are higher or lower than one another, but the differences between them are not the same. So the satisfaction ratings are ordinal level of measurement.

For each of the following, determine whether the group is a sample or a population. -The participants in a study of a new cholesterol drug. -The drivers who received a speeding ticket in Kansas City last month. -People on welfare in Cook County (Chicago), Illinois. -The 30 stocks that make up the Dow Jones Industrial Average.

-The study participants are only a portion of those who may use the new drug. So they are a sample. -The drivers who received a speeding ticket is the entire group of interest. So they are a population. -People on welfare in Cook County is the entire group of interest. So they are a population. -These 30 large publicly owned US companies' shares are only a portion of those traded during a standard trading session in the US stock markets. So they are a sample.

A baseball player gets a hit in 30 out of 100 times at bat. The probability is 0.300 that he gets a hit in his next at bat.

Empirical

The probability of an earthquake in northern California in the next 10 years above 5.0 on the Richter Scale is 0.80.

Empirical

What is the level of measurement for each of the following variables? Student IQ ratings. Distance students travel to class. The jersey numbers of a sorority soccer team. A student's state of birth. A student's academic class—that is, freshman, sophomore, junior, or senior. Number of hours students study per week.

The difference between Student IQ ratings is a constant size. However there is no meaningful zero point. So they are interval level of measurement. The distance students travel to class has a significant zero point and the ratio between two distances is meaningful. So they are ratio level of measurement. Jersey numbers are different from each other but have no meaning other than identification of particular players. So they are nominal level of measurement. States of birth are different from each other but have no particular order to them. So they are nominal level of measurement. One class rank is higher or lower than another, but the differences between the groups are not the same. So class rank is ordinal level of measurement. The number of hours students study per week has a significant zero point and the ratio between two numbers meaningful. So they are ratio level of measurement.