For a month, Mrs. McCoy's science class recorded the low temperature each day.

Daily low temperature (°F)
40
44
48
52
56
60
What was the upper quartile of the temperatures?
°F

1 answer

To find the upper quartile (Q3) of the daily low temperatures, we first need to arrange the temperatures in ascending order (which they already are):

  • 40°F
  • 44°F
  • 48°F
  • 52°F
  • 56°F
  • 60°F

Next, we calculate the median (Q2) of the dataset. Since there are 6 numbers, the median will be the average of the 3rd and 4th numbers:

\[ \text{Median (Q2)} = \frac{48 + 52}{2} = \frac{100}{2} = 50°F \]

Now, the upper quartile (Q3) is the median of the upper half of the dataset. The upper half consists of the values greater than the median: 52°F, 56°F, and 60°F.

To find Q3, we take the median of the upper half:

\[ \text{Upper half: } 52°F, 56°F, 60°F \]

Since there are 3 numbers in this upper half, Q3 is the middle number:

\[ \text{Q3} = 56°F \]

Thus, the upper quartile of the temperatures is 56°F.