a) Use the information in the table to calculate John’s typing time.
b) What percentage of students had an efficiency greater than two-thirds?
c) What should Sue’s total time be for her to have an efficiency of two-thirds?
d) Calculate Bob’s typing rate in words per minute.
e) Charlene earns £7.20 per hour. How much would she earn for producing
a 300-word report?
f) Which student has the total time that is nearest to the mean total time?
g) Find the median total time and explain why it is an appropriate statistic
to use for the total times.
h) Draw a scatter graph of total time against typing time to compare
the students’ results, plotting each time correct to the nearest 100 seconds.
i) By inspection, draw a line of best fit on the scatter graph.
j) Use your scatter graph to estimate the total time which corresponds
with the mean typing time.
k) Another student, Sean, has a typing time of 587 seconds and a total time
of 976 seconds. Describe briefly a method to estimate Sean’s efficiency.
Write your estimate as a fraction.
l) A new student, Neena, has an efficiency percentage of 45.7 and would like
to improve to 60%. She is quick at typing, with a time of 480 seconds, and
intends to focus on improving her total time.
Calculate how many seconds she will need to take off her total time
to achieve her efficiency goal.
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