How Many Did We Measure? Reporting the Number of Observations
I can report how many data values were collected (called n).
📘 Word Bank + Sentence Frames
data value observation number of observations (n) data set
The idea: Each thing we measured or counted is one observation.
The total count of observations is called n.
- To find n, count every data value (count every dot, every number).
- Frame: "We collected ____ observations, so n = ____."
👀 See It: A Worked Example
Students were asked: "How many pets do you have?" Each ● is one student's answer:
0 pets: ● ●
1 pet : ● ● ● ●
2 pets: ● ● ●
3 pets: ●
Count all the dots: 2 + 4 + 3 + 1 = 10. So n = 10 students were surveyed.
✏️ Your Turn — A new data set
Minutes of reading last night: 15, 20, 20, 30, 10, 25, 20, 0
0 of 3 checks complete
1. How many observations (n) are in this data set?
2. What does n count?
3. In the pets dot plot above, what was n?
💬 Explain Your Thinking
Tell a partner how you found n:
"To find n, I blank. In this data set, n = blank."