Business and Economics Statistics - Essay Example

The descriptive statistic can be obtained using the corresponding option in Excel Data Toolkit (Anderson, Sweeney, Williams, Camm, and Cochrane, 2015). The results are given in the table below. The mean and the median are close to each other, and the skewness is not significant. The stem and leaf diagram shows that the largest number of results is between 2700 and 2800, which is close to the mean value. The data distribution is close to normal with left skewness.

To develop the table of frequencies the number of classes and class range has to be defined. The number of classes can be defined as a square root of the number of measurements. As N = 41, the number of classes will be 6.4, which is rounded to 7. The class width is found by dividing the range by the number of classes. Thus, the class range is 2514,643/7 = 359,23 (rounded to 359). The class midpoint is found as the sum of the upper and lower boundaries of the class divided by 2. Relative frequency is obtained by dividing frequency by the total number of measurements. Cumulative relative frequency is defined as a sum of frequencies for the data smaller than the upper boundary of the class (Mendenhall, Beaver, and Beaver, 2013).

The histogram is built in the coordinates of class midpoint – frequency. The histogram supports the statement that the data distribution is left-skewed. The histogram also confirms that the range between 2700 and 2800 contains the largest number of measurements.

Ogive can be built in coordinates cumulative (or cumulative relative) frequency – upper-class boundary (Mendenhall, Beaver, and Beaver, 2013). The ogive shows that the small number of data is located in the range between 3500 and 4500. This also supports the statement about the left skewness of the data. The highest increase in the frequency is in the range of 2600-3000. Read More