Daily Practice · Higher
February 2023 5-a-day
Printing for a group?
The batch download puts all 2 tiers' February 2023 sheets in a single PDF, each tier behind its own divider page - 56 sheets in one file.
Every sheet in February 2023
The same date always regenerates the same five questions, so a sheet you print today is the sheet a classmate prints tomorrow.
- 1st February 2023Test scores are normally distributed with mean 65 and standard deviation 8. Estimate the percentage of students scoring between 65 and 81.
- 2nd February 2023For a data set, Sxy = 30, Sxx = 50, Syy = 40. Calculate the PMCC to 3 significant figures.
- 3rd February 2023A class interval has width 5 and frequency 20. Find the frequency density.
- 4th February 2023A data set has Q1 = 20 and Q3 = 32. Is a value of 55 an outlier? Use the 1.5 x IQR rule.
- 5th February 2023P(A) = 1/2, P(B) = 1/3, P(A and B) = 1/6. Find P(A or B).
- 6th February 2023The table shows ages, in years, of 50 people at a gym: 10-20 (freq 6), 20-30 (freq 18), 30-40 (freq 16), 40-50 (freq 10). Estimate the mean age.
- 7th February 2023What is wrong with the question 'How old are you and do you smoke?'
- 8th February 2023Find the 3-point moving average of 10, 14, 18.
- 9th February 2023P(A) = 0.4 and P(B) = 0.35, where A and B are mutually exclusive. Find P(A or B).
- 10th February 2023A histogram has bars of equal width. True or false: the height of each bar represents the frequency for that class.
- 11th February 2023Name the five values needed to draw a box plot.
- 12th February 2023A data set of 10 house prices, in thousands of pounds, has a mean of 210 without an outlier of 900 included, but a mean of 279 when the 900 is included. Explain why a statistician might exclude the 900 when reporting a typical house price.
- 13th February 2023A normally distributed data set has mean 40 and standard deviation 3. Estimate the percentage of values above 43.
- 14th February 2023A regression line y = 12 + 1.5x is used to predict y when x = 200, even though the original x-values ranged only from 5 to 20. Explain why this prediction may be unreliable.
- 15th February 2023A histogram has classes 20-25 (frequency density 4), 25-35 (frequency density 2.4), 35-50 (frequency density 1.6). Find the total number of data values represented.
- 16th February 2023A data set has Q1 = 12 and Q3 = 20. Calculate the IQR and the upper outlier boundary.
- 17th February 2023Out of 50 people surveyed, 20 like tea, 25 like coffee, and 10 like both. Find the probability that a randomly chosen person likes tea or coffee.
- 18th February 2023A class interval 0-10 has frequency 6. Find frequency x midpoint.
- 19th February 2023A survey question offers the response options 'Never, Sometimes, Always'. State one improvement that could be made.
- 20th February 2023Find the 4-point moving average of 12, 16, 20, 10.
- 21st February 2023Are 'rolling an even number' and 'rolling a 5' on a normal six-sided dice mutually exclusive?
- 22nd February 2023A histogram for exam scores has bars of equal width 10 marks, covering 0-10, 10-20, 20-30, 30-40, with heights 2, 8, 15, 5. How many students took the exam?
- 23rd February 2023A box plot shows minimum 4 and maximum 36, with median 20. State the range of the data.
- 24th February 2023A data set has lower quartile Q1 = 20 and upper quartile Q3 = 32. Using the rule 'outlier if more than 1.5 x IQR beyond Q1 or Q3', find the outlier boundaries.
- 25th February 2023A normal distribution has mean 50 and standard deviation 5. What range of values contains approximately 68% of the data?
- 26th February 2023For a data set, Sxy = 45 and Sxx = 60. Find the gradient b of the regression line.
- 27th February 2023A histogram bar has height (frequency density) 2.5 and covers the interval 0-8. Find the frequency it represents.
- 28th February 2023A cumulative frequency table gives Q1 = 18, median = 25, Q3 = 34 for the ages of 60 people at a conference. Calculate the IQR and state the upper outlier boundary.