Daily Practice · Foundation
October 2020 5-a-day
Printing for a group?
The batch download puts all 2 tiers' October 2020 sheets in a single PDF, each tier behind its own divider page - 62 sheets in one file.
Every sheet in October 2020
The same date always regenerates the same five questions, so a sheet you print today is the sheet a classmate prints tomorrow.
- 1st October 2020On a time series graph, what is always plotted on the horizontal axis?
- 2nd October 2020Group A has a risk of 0.08 of an event happening; Group B has a risk of 0.02. Find the relative risk of Group A compared with Group B.
- 3rd October 2020A bag has 3 red, 4 green and 5 blue balls (12 total). One ball is removed at random and is blue. A second ball is then removed. Find P(second ball is red given the first ball was blue).
- 4th October 2020A 3D pie chart is used to show market share. Explain why 3D charts can be misleading.
- 5th October 2020A table has class intervals with frequency x midpoint totals of 45, 120, 90 and frequencies 5, 8, 6. Find the estimated mean.
- 6th October 2020Explain why a pilot survey should be carried out before the full survey is sent out.
- 7th October 2020Find the 4-point moving average of 12, 16, 20, 10.
- 8th October 2020P(rain) = 0.3 and P(snow) = 0.05 on a given day, and rain and snow are mutually exclusive that day. Find P(rain or snow).
- 9th October 2020Using the same histogram, how many students scored between 10 and 30 marks?
- 10th October 2020A box plot has lower quartile 10 and upper quartile 22. Find the interquartile range.
- 11th October 2020The heights (cm) of 6 plants are: 15, 18, 16, 14, 17, 150. Find the mean of the remaining values after removing the outlier.
- 12th October 2020Explain why a crude rate is more useful than a raw total, such as the total number of deaths, when comparing two towns of different sizes.
- 13th October 2020A factory has 400 workers: 160 in production, 120 in packing and 120 in admin. A stratified sample of 50 workers is needed. Find how many should be sampled from packing.
- 14th October 2020Using the same table (0:4, 1:10, 2:4, 3:2), find the mean number of siblings.
- 15th October 2020The mean rainfall in April was 45 mm with a range of 20 mm; in May it was 45 mm with a range of 8 mm. Compare April and May.
- 16th October 2020A cost index for electricity, relative to the same base year, was 120 in 2021 and 150 in 2023. Find the percentage increase in the cost of electricity from 2021 to 2023 (not from the base year).
- 17th October 2020The probability that a train is late is 0.15. Out of 200 trains, how many would you expect to be late?
- 18th October 2020The probability that a machine produces a faulty item is 0.04. Out of 300 items, how many would you expect to be faulty?
- 19th October 2020A box has 3 faulty bulbs out of 10. Two bulbs are chosen without replacement. Find the probability at least one is faulty.
- 20th October 2020In a pyramid, the bars for ages 65+ are unusually long compared with younger age bands. Give one possible reason.
- 21st October 2020A data set has mean 12, median 12, mode 12. Describe its skew.
- 22nd October 2020A sample of 80 light bulbs from a batch of 2000 found 4 were faulty. Estimate the number of faulty bulbs in the whole batch.
- 23rd October 2020The mean of 6 numbers is 15. Five of the numbers are 10, 12, 14, 18, 20. Find the sixth number.
- 24th October 2020State one advantage of random sampling.
- 25th October 2020What is meant by a control variable?
- 26th October 2020Values of 12, 18, 25, 31, 9, 22, 15 are grouped using intervals 0 <= x < 10, 10 <= x < 20, 20 <= x < 30, 30 <= x < 40. State the frequency of the interval 10 <= x < 20.
- 27th October 2020A pie chart shows four categories with angles 90, 120, 60 and x degrees. Find x.
- 28th October 2020Events A and B are mutually exclusive with P(A) = 0.3 and P(B) = 0.25. Find P(A or B).
- 29th October 2020Explain why estimating a y-value for x = 50 would be unreliable if all the plotted data only covers x-values from 0 to 20.
- 30th October 2020Two variables have a correlation coefficient close to 0. What does this suggest?
- 31st October 2020The Spearman's rank correlation coefficient between temperature and ice cream sales for 8 days is rs = 0.95. Describe the correlation.