Analytical Skills for Business

Analytical Skills for Business

Question No. 1

A frequency distribution is a table in which data is organized into classes, i.e. in groups of values ??that describe a property of the data and displays the number of observations of all data that fall in each of the classes. The frequency table helps to group any numeric data type. In principle, the frequency table detailing each of the different values ??in the data set along with the number of occurrences, i.e. their absolute frequency. It can be supplemented with the so-called absolute frequency relative frequency, the frequency indicating a percentage of total data. In quantitative variables are distinguished on the other hand the simple frequency and cumulative frequency. The frequency table can be plotted in a histogram. Normally on the vertical axis is placed in the frequencies and horizontal intervals of values.

Question1 (Binned)

Frequency

Percent

Valid Percent

Cumulative Percent

Valid

<= 685

1

2.1

2.1

2.1

686 - 753

2

4.2

4.2

6.2

754 - 821

1

2.1

2.1

8.3

822 - 890

14

29.2

29.2

37.5

891 - 958

16

33.3

33.3

70.8

959 - 1026

9

18.8

18.8

89.6

1027 - 1094

5

10.4

10.4

100.0

Total

48

100.0

100.0

The table above shows the frequency distribution for the given data set, according to my registration the third digit is 1, therefore, X is replaced by one. Further, the number has been grouped into the classes; there were 48 observations in total. We have divided the results of life of 100-watt light bulbs into 7 intervals, and count the number of results in each interval. In this case, the intervals are the length of life (in hours) of a sample of forty eight 100-watt light bulbs produced by a manufacturer.

The main purpose of descriptive statistics is to summarize data sets using summary tables or graphs, in order to identify the characteristic behavior of a phenomenon and facilitate scrutiny. Any research undertaken can lead to accumulation of quasi-quantitative values ??and qualitative for the various measurements made. This possibility makes the statistics a vital tool for the treatment of amounts of data through summary tables known as "Frequency Tables". When data is grouped, the interpretation turns out to be easier.

Histogram of the Frequency Distribution

A histogram is a graphical representation of a variable in the form of bars. They are used for continuous variables or discrete variables, with a large number of data, and are grouped into classes. The abscissa axis rectangles are constructed which are based on the interval width, and height, the absolute frequency of each interval. The surface of each bar is proportional to the frequency of the plotted values.

The histogram above for the frequency distribution shows that maximum numbers of the frequencies i.e. 16 were observed in the fifth interval i.e. 891 - 958, the second highest frequencies i.e. 14 were observed in the 4th interval i.e. 822-890. However, the lowest frequencies were found in the 1st and 2nd interval, histograms are commonly used as their standard format makes them easy to understand and encourage communication between users, unfamiliar same statistical methods. The curve in the histogram shows that the data is not normally distributed, as the curve is not perfectly bell shaped.

Question 2 (10 marks)

Sales of 2010 model light trucks ...