A meteorologist recorded the following temperatures: {71,74,81,78,67,69,64} . Which best describes the variability of the temperature?(1 point) Responses The IQR is 17, making the temperatures easy to predict because the data values are close together. The IQR is 17, making the temperatures easy to predict because the data values are close together. The range is relatively high, showing that the temperature will likely be as low as 47 degrees in the next temperature reading. The range is relatively high, showing that the temperature will likely be as low as 47 degrees in the next temperature reading. The range is relatively low, indicating a low variability in the temperature. The range is relatively low, indicating a low variability in the temperature. The IQR is 11, indicating a fairly high variability for the temperatures for half of the recorded days.

1 answer

To assess the variability of the temperatures recorded {71, 74, 81, 78, 67, 69, 64}, we'll calculate both the range and the interquartile range (IQR).

  1. Calculating the Range:

    • The range is given by the maximum temperature minus the minimum temperature.
    • Maximum: 81
    • Minimum: 64
    • Range = 81 - 64 = 17
  2. Calculating the IQR:

    • First, we need to organize the data in ascending order: {64, 67, 69, 71, 74, 78, 81}.
    • The median (Q2) is the fourth number, which is 71.
    • To find Q1 (the first quartile), take the median of the first half: {64, 67, 69}. The median of these numbers is 67.
    • To find Q3 (the third quartile), take the median of the second half: {74, 78, 81}. The median of these numbers is 78.
    • IQR = Q3 - Q1 = 78 - 67 = 11.

Now let's analyze the provided statements:

  1. The IQR is 17, making the temperatures easy to predict because the data values are close together.

    • Incorrect. The IQR is 11, not 17.
  2. The range is relatively high, showing that the temperature will likely be as low as 47 degrees in the next temperature reading.

    • Incorrect. The range is 17, not particularly high and does not suggest a temperature as low as 47 degrees based on the data provided.
  3. The range is relatively low, indicating a low variability in the temperature.

    • Incorrect. The range is 17, which does not indicate low variability.
  4. The IQR is 11, indicating a fairly high variability for the temperatures for half of the recorded days.

    • Correct. The IQR is indeed 11, which suggests that there is variability within the central half of the data.

So, the best description of the variability of the temperature is: "The IQR is 11, indicating a fairly high variability for the temperatures for half of the recorded days."