Extra Unit 1 Test

Question 1

Calculating mean with class ranges

Answer 1

Take the midpoint for each class range and then take the mean of those midpoints

Question 2

Applying chebyshev’s theorem

Answer 2

Lower bound minus average divided by the standard deviation

Upper bound minus average divided by the standard deviation

Question 3

Relative frequency

Answer 3

It is the frequency of one class as a percentage or fraction compared to the frequency of the other classes

35-40 has a frequency of 6 and the cumulative frequency is 42, so the relative frequency is 1/7

Question 4

Class width

Answer 4

The difference between the lower class limit of one class and the lower class limit of the next class

10-13
14-17 class width being 14-10=4

Question 5

Class boundaries

Answer 5

The sum of the upper limit of one class and the lower limit of the next class divided by 2

23-25
26-28 25+26/2=

Question 6

Finding a data value using the mean

Answer 6

(3+4+5+x)/4=35 you would multiply both sides by 35 etc

Question 7

Calculation of percentage

Answer 7

Find all values less than or equal to given value, and divide that by the total number of values