Standard Deviation and Data

2. Based on the scale of measurement for each variable listed below, which measure of central tendency is most appropriate for describing the data?

are more uncertain than the others? How could uncertainty be worked into the analysis? Is

Theoretically from the recorded data the calculated mean, median, and mode will be the most accurate representation of the real world value. The difference between the highest recorded value and lowest recorded value is the range in the set of data. Standard deviation (s) is a quantity calculated to indicate an extend of deviation for a group of data as a whole (Marshall). This is calculated using:

Mean is the average of a group of scores (Woolfolk, 2014). Mean and average are used interchangeably. To find the mean, a teacher will add all of the scores together and divided by the number of tests. For example, a teacher wants to find the mean of the spelling test, the spelling test scores are as the following, 10, 8, 7, 8, 10, 10, 6, 5, 7, and 5. The first step is to add all of the scores together (76). The second step is to divided by the number of tests (10), the quotient is the mean (7.6). The first math equation is 10+8+7+8+10+10+6+5+7+5=76. The second math equation is 76/10=7.6. The mean of the

5. Give the standard deviation for the mean and median column. Compare these and be sure to identify which has the least variability?

12. _____ For a given population, confidence intervals constructed from larger samples tend to be narrower than those constructed from smaller samples. Which statement below best describes why this is true? (A) The variability of the sample mean is less for larger samples. (B) The z-value for larger samples tends to be more accurate. (C) The population variance is larger for large populations. (D) As the sample size increases, the z-value (or t-value) becomes smaller. A machine dispenses potato chips into bags that are advertised as containing one pound of product. To be on the safe side, the machine is supposed to be calibrated to dispense 16.07 ounces per bag, and from long time observation, the distribution of the fill-weights is known to be approximately normal and the process is known to have a standard deviation of 0.15 ounces.

5. Find the sample variance s2 for the following sample data. Round your answer to the nearest hundredth.

4. a) An example of statistics is the statement “Between the ages of 15 and 24, they take their lives five times as often.”

It is one of the most popular and well known measures of central tendency. It can be used with both discrete and continuous data, although its use is most often with continuous data

C. The researchers analyzed the data as though it were at the interval/ratio level since they calculated means (the measure of central tendency that is appropriate only for interval/ratio level data) and standard deviations (the measure of dispersion for interval/ratio data) to describe their study variables.

The following data are the base salaries, in thousands of dollars, of 50 chief executive officers

When a scatter plot's (x,y) points are all pretty close to the "line of best fit", then how would you describe the relationship between the points?

Placed students had higher grades because their course grade mean was higher and the standard deviation was lower than the continuing students. This means that the average distance to the mean was every 1.04 of each student making the gap longer than the average distance of placed students which was .62.

Sample is the 33,160 responses. The population seemed to be the entire population. The sample is a voluntary response sample because subscribers could choose to respond or not. It is not likely to be a representation of the greater population.

5. The arithmetic mean is only measure of central tendency where the sum of the deviations of each value from the mean will always be zero