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Flashcards · Maths · Statistics

Averages and Range

16 cards

  1. How do you calculate the mean?

    Add all the values and divide by the number of values.

  2. How do you find the median?

    Put the values in order and take the middle one, or the mean of the two middle values.

  3. What is the mode?

    The most common value.

  4. What is the range?

    The largest value minus the smallest value.

  5. Which average is affected most by an outlier?

    The mean.

  6. When is the mode the best average?

    For non-numerical data, such as the most popular colour.

  7. What does a smaller range tell you?

    The data is more consistent.

  8. How do you find the mean from a frequency table?

    \(\sum fx\) divided by \(\sum f\).

  9. How do you find the median from a frequency table of \(n\) values?

    Find the \(\dfrac{n + 1}{2}\)th value using cumulative frequencies.

  10. What is the mode in a frequency table?

    The value with the highest frequency.

  11. What is the mid-point of the class \(20 < w \leq 40\)?

    30.

  12. How do you estimate the mean of grouped data?

    Multiply each mid-point by its frequency, add up, and divide by the total frequency.

  13. Why is the mean of grouped data only an estimate?

    The exact values in each class are not known.

  14. Five numbers have a mean of 8. What is their total?

    40.

  15. What is the modal class?

    The class with the highest frequency.

  16. Why should you say "on average" in a comparison?

    The answer is about typical values, not every item.