Averages, Ranges & Data (Edexcel GCSE Maths: Foundation): Flashcards

Exam code: 1MA1

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  • How do you find the mean of a set of numbers?

Cards in this collection (28)

  • How do you find the mean of a set of numbers?

    To find the mean of a set of numbers:

    1. Add the values together.

    2. Divide by the total number of values.

  • How do you find the median of a set of numbers?

    To find the median of a set of numbers:

    1. Put the numbers in order.

    2. Find the middle number.

    If there are two middle numbers then the median is the midpoint of those numbers.

  • How do you find the mode of a set of numbers?

    The mode of a set of numbers is the value that appears the most.

  • True or False?

    There can be more than one median value in a data set.

    False.

    There can not be more than one median value in a data set. The median is the middle value.

    The only average that can have more than one value is the mode.

  • True or false?

    The mean is affected by extreme values.

    True.

    The mean is affected by extreme values.

  • True or false?

    The median is affected by extreme values.

    False.

    The median is not affected by extreme values.

  • How can you find the total of all data values if you know the mean and the number of values?

    E.g. if the mean of a set of 25 values is 3.7, what is the total of all values in the data set?

    If you know the mean and number of values, you can calculate the total of values by rearranging the mean formula:

    • total space of space values equals mean space cross times space number space of space values

    E.g. if the mean of a set of 25 values is 3.7, then the total of all values in the data set is 3.7 cross times 25 equals 92.5.

  • How can you find the number of data values if you know the mean and the total of the values?

    E.g. if the total of a set of data values is 66 and the mean is 8.25, how many data values are there?

    If you know the mean and total of the data values, you can calculate the number of values by rearranging the mean formula:

    • number space of space values equals fraction numerator total space of space values over denominator mean end fraction

    E.g. the total number of data values in a set of data with a total of 66 and mean of 8.25 is fraction numerator 66 over denominator 8.25 end fraction equals 8.

  • How can you find the new mean of a data set if a new data item is added to the set?

    E.g. a data set of 12 items has a mean of 5.7.
    A new data item of 9.6 is added to the set.
    What is the new mean?

    To find the new mean of a data set if a new data item is added to the set:

    1. Find the total of the current data set: total space of space values equals mean space cross times space number space of space values

    2. Add the new data item

    3. Divide by the new total number of data items

    E.g. for a data set of 12 items and a mean of 5.7, the total of the values is 12 cross times 5.7 equals 68.4.
    Therefore when a new data item of 9.6 is added to the set, the new mean is fraction numerator 68.4 plus 9.6 over denominator 13 end fraction equals 6.

  • How do you find the mean from a frequency table?

    To find the mean from a frequency table:

    1. Include a column for (value cross times frequency).

    2. Add the values in this column.

    3. Divide the sum by the total frequency.

  • How do you find the median from a frequency table?

    To find the median from a frequency table:

    1. Make sure the values in the table are in order.

    2. Find the fraction numerator n plus 1 over denominator 2 end fractionth value, where n is the total frequency.

  • How do you find the mode from a frequency table?

    To find the mode from a frequency table, look for the value with the highest frequency.

  • How do you estimate the mean from grouped data?

    To estimate the mean from grouped data:

    1. Find the midpoint of each class.

    2. Calculate (midpoint × frequency) for each class.

    3. Sum the (midpoint × frequency) values.

    4. Divide the sum by the total frequency.

  • What is a class interval?

    A class interval is a range of values within which data points are grouped together.

  • True or false?

    The actual mean can be calculated from grouped data.

    False.

    Only an estimate of the mean can be calculated from grouped data.

  • How do you find the class interval containing the median from grouped data?

    To find the class interval containing the median from grouped data:

    1. Find the position of the median using n over 2, where n is the total frequency.

    2. Use the table to determine the class interval containing this position.

  • How do you find the modal class interval from grouped data?

    To find the modal class interval from grouped data, look for the class interval with the highest frequency.

  • What does the phrase "estimate the mean" usually indicate on an exam question?

    The phrase "estimate the mean" usually indicates that the data is grouped, and that you should use the midpoint method to estimate the mean.

  • What is qualitative data?

    Qualitative data is data that is usually given in words, not numbers, to describe something.

    For example, the colour of a teacher's car.

  • True or False?

    The number of pets that a student has is an example of qualitative data.

    False.

    The number of pets that a student has is an example of quantitative data as it is numerical.

  • What is discrete data?

    Discrete data refers to data that can only take certain numerical values. It is often (but not always) data that can be counted.

    Examples of discrete data include:

    • Number of pets

    • Shoe size

    • Number of petals on a flower

  • What is continuous data?

    Continuous data refers to data that can take any numerical value within a range. It is usually data that needs to be measured.

    Examples of continuous data include:

    • Height

    • Weight

    • Time taken to complete a jigsaw

  • True or False?

    Age is always considered to be continuous data.

    False.

    Age can be discrete or continuous depending on the context or how it is defined.

    If you mean how many years old a person is, then it is discrete.

    If you mean how long a person has been alive, then it is continuous.

  • True or False?

    Primary data is data that has been collected by the person carrying out the research, such as through questionnaires, surveys, or experiments.

    True.

    Primary data is data that has been collected by the person carrying out the research, such as through questionnaires, surveys, or experiments.

  • What is secondary data?

    Secondary data is data that has been collected previously, found on the internet or through other research sources.

    For example, the number of wins for each football team in a previous World Cup.

  • True or False?

    A population always refers to a number of people or animals.

    False.

    A population does not necessarily refer to a number of people or animals.

    It can refer to any set of items being studied, such as all the different makes and models of mobile phones in the world.

  • What is a sample?

    A sample is a selected part (called a subset) of the population which is used to collect data from.

  • State one advantage of using a sample for data collection.

    One advantage of using a sample for data collection is that it is quicker to collect the data compared to using the entire population.

    Alternative reasons are that it is cheaper or it is easier to analyse as there is less data.

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