STATISTICS

Continuous

----- data is usually found by measuring (not counting) and rounded to a suitable degree of accuracy.

Statistics

----- is concerned with the collection, ordering and analysis of data.

Frequency

----- is defined as the number of times an item or an event occurs.

Class boundaries

----- separate one class from another. It usually has the formula: {1/2(upper class limit of one class + lower class limit of the next class)}

SOLUTION: Total frequency/2 = 40/2 = 20 , Add the frequencies from the lower class up to half the total frequency (i.e. 3 + 5 + 9 + 12 = 29). ANSWER: 145 - 153

Consider the data below: "CLASS: 118 - 126, 127 - 135, 136 - 144, 145 - 153, 154 - 162, 163 - 171, 172 - 180" "FREQUENCY: 3, 5, 9, 12, 5, 4, 2" Estimate the median range without necessarily drawing a histogram to represent the above data.

for a histogram there is no gap between the rectangles

Continue the following statement: "The main difference between a histogram and a bar chart is that ----- ?"

1. Find the difference between (upper class limit of one class and the lower class limit of the next class) i.e. (40 - 39 = 1) and half of the difference i.e. (1/2 = 0.5). 2. Subtract the 0.5 obtained from the lower class limit of each class and add the 0.5 to the upper class limit of each class to obtain the class boundaries. i.e. ((i) 35 - 39 = 34.5 - 39.5) and ((ii) 40 - 44 = 39.5 - 44.5) ANSWERS: (i) 34.5 - 39.5 and (ii) 39.5 - 44.5 - 39

Find the class boundary of the following given; (i)Marks = 35 - 39, Frequency = 3, Class boundary = -----? (ii)Marks = 40 - 44, Frequency = 2, Class boundary = -----? NB: Both (i and ii) form the same frequency table.

ANSWERS: (i) 940 - 1040 and (ii) 1040 - 1140

Find the class boundary of the following given; (i)Marks = 980 - 1000, Frequency = 10, Class boundary = -----? (ii)Marks = 1080 - 1100, Frequency = 15, Class boundary = -----? NB: Both (i and ii) form the same frequency table.

1/2(35 + 39) = 37

Find the class mid-value of the class interval: 35 - 39

ANSWERS: (i) 5 and (ii) 5

Find the class size of the following given; (i)Marks = 35 - 39, Frequency = 3, Class boundary = 34.5 - 39.5, Class size = -----? (ii)Marks = 40 - 44, Frequency = 2, Class boundary = 39.5 - 44.5 - 39, Class size = -----? NB: Both (i and ii) form the same frequency table.

SOLUTION: 20, 26, 27, 30, 34, 41, 41, 64, 65, 72, 85 (i.e; n = 11) Lower quartile = 1/4 (11 + 1) = 3rd value, (27) Median = 1/2 (11 + 1) = 6th value, (41) Upper quartile = 3/4 (11 + 1) = 9th value, (65)

Find the first (lower), second (median) and third (upper) quartiles of the following set of numbers; 41, 26, 27, 64, 72, 65, 85, 20, 41, 30, 34

SOLUTION: [(0 + 2 + 3 + 4 + 5 + 4)/6] = 3

Find the mean of the following set of numbers; 0, 2, 3, 4, 5 and 4

ANSWER: 3

Find the mode of the following numbers; 2, 3, 2, 3, 4, 3, 5

class frequency / class size

Frequency density is given as: ----- ?

Measures of central tendency

The ----- are the averages of the frequency distribution.

Class mid-value or midpoint

The ----- is the average of the lower and upper class boundaries. i.e. {1/2(lower class limit + upper class limit)}

Class size or width

The ----- is the difference between the lower and upper class boundaries of a class interval.

Quartiles

The ----- of a grouped data divide the set of data into four equal parts. It is sometimes denoted by; Q1 = 1/4(∑f)

Mean

The ----- of a set of numbers, is the average of the numbers.

Median

The ----- of a set of numbers, is the middle value or the arithmetic mean of the two middle values, if they are arranged in increasing order of magnitude.

Mode (or the modal value)

The ----- of a set of numbers, is the number which occurs most frequently.

Inter-quartile and semi-interquartile

The ----- range is given as; upper quartile (Q3) - lower quartile (Q1) while the ----- range is given as; 1/2(Q3 - Q1)

Class interval

The range of possible values for a group or a class is called its ----- ?

Deciles

The values which divide a set of data into 10 equal parts are called ----- ? [It is mostly denoted as; n/10((∑f))]

Percentiles

The values which divide a set of data into 100 equal parts are called ----- ? [It is mostly denoted as; n/100((∑f))]

Discrete data

Values of ----- are restricted to only certain, exact distinct numbers (but not measurement).