Daily Practice · Higher
August 2015 5-a-day
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The batch download puts all 2 tiers' August 2015 sheets in a single PDF, each tier behind its own divider page - 62 sheets in one file.
Every sheet in August 2015
The same date always regenerates the same five questions, so a sheet you print today is the sheet a classmate prints tomorrow.
- 1st August 2015A series of 4-point moving averages is 45, 48, 52, 55. Describe the trend shown by these values.
- 2nd August 2015A bag has only red, blue and green counters. P(red) = 0.5 and P(blue) = 0.2. Find P(green).
- 3rd August 2015State one reason why a histogram has no gaps between its bars, unlike a bar chart.
- 4th August 2015Box plot A has an interquartile range of 8 and box plot B has an interquartile range of 15. What does this tell you about the spread of the middle 50 percent of each data set?
- 5th August 2015Using the boundaries from the previous question (2 and 50), state whether a value of 55 in the data set would be classed as an outlier.
- 6th August 2015Test scores are normally distributed with mean 65 and standard deviation 8. Estimate the percentage of students scoring between 65 and 81.
- 7th August 2015For a data set, Sxy = 30, Sxx = 50, Syy = 40. Calculate the PMCC to 3 significant figures.
- 8th August 2015A class interval has width 5 and frequency 20. Find the frequency density.
- 9th August 2015A data set has Q1 = 20 and Q3 = 32. Is a value of 55 an outlier? Use the 1.5 x IQR rule.
- 10th August 2015P(A) = 1/2, P(B) = 1/3, P(A and B) = 1/6. Find P(A or B).
- 11th August 2015The 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.
- 12th August 2015What is wrong with the question 'How old are you and do you smoke?'
- 13th August 2015Find the 3-point moving average of 10, 14, 18.
- 14th August 2015P(A) = 0.4 and P(B) = 0.35, where A and B are mutually exclusive. Find P(A or B).
- 15th August 2015A histogram has bars of equal width. True or false: the height of each bar represents the frequency for that class.
- 16th August 2015Name the five values needed to draw a box plot.
- 17th August 2015A 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.
- 18th August 2015A normally distributed data set has mean 40 and standard deviation 3. Estimate the percentage of values above 43.
- 19th August 2015A 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.
- 20th August 2015A 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.
- 21st August 2015A data set has Q1 = 12 and Q3 = 20. Calculate the IQR and the upper outlier boundary.
- 22nd August 2015Out 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.
- 23rd August 2015A class interval 0-10 has frequency 6. Find frequency x midpoint.
- 24th August 2015A survey question offers the response options 'Never, Sometimes, Always'. State one improvement that could be made.
- 25th August 2015Find the 4-point moving average of 12, 16, 20, 10.
- 26th August 2015Are 'rolling an even number' and 'rolling a 5' on a normal six-sided dice mutually exclusive?
- 27th August 2015A 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?
- 28th August 2015A box plot shows minimum 4 and maximum 36, with median 20. State the range of the data.
- 29th August 2015A 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.
- 30th August 2015A normal distribution has mean 50 and standard deviation 5. What range of values contains approximately 68% of the data?
- 31st August 2015For a data set, Sxy = 45 and Sxx = 60. Find the gradient b of the regression line.