Stem and Leaf plots 
Stem and Leaf Plot Analysis
Title and Context
The chart is titled "Daily Average Temperature Washington DC, April 2010".
It displays the average temperature for each day in Washington DC during the month of April, which has 30 days.
Structure of the Stem and Leaf Plot
The plot has a left column labeled "Stem" and a right column labeled "Leaf".
Each number in the "Stem" column represents the tens place of the temperature values.
Each number in the "Leaf" column represents the ones place of the temperature values.
The values are separated by commas for clarity in the leaf column.
Understanding the Data Representation
Each entry in the leaf column, when combined with the corresponding stem, forms a two-digit number that indicates the average temperature for a specific day in April.
Example Interpretation:
In the second row of the plot, by combining the stem and the leaves (e.g., stem 5 with leaves 3, 5, 3, 5, 9), the represented temperatures are:
53, 55, 53, 55, 59.
Key Question Analysis
The critical question posed is: "On how many days in April was the temperature in Washington DC above 59 degrees?"
Clarification of the Question:
The question implies that we need to identify all temperature readings that are 60 degrees or higher.
Data Extraction from the Plot
Examining the Rows:
Sixth Row: All entries are above 60 degrees. The entry details include:
60, 65, 61, 66, 69, 61, 64, 62, 63, 65, 66
Row Count: There are 11 entries here.
Seventh Row: Also contains values above 60 degrees with the following entries:
76, 77, 70, 71
Row Count: There are 4 entries here.
Fifth Row: Does not contribute since it contains no entries above 59 degrees.
Conclusion
Adding the entries:
Total number of days where the temperature was above 59 degrees:
11 (from the sixth row) + 4 (from the seventh row) = 15
Therefore, the temperature in Washington DC was above 59 degrees on 15 days in April 2010.