Let's solve this problem step by step, calculating the mean height and determining the number of students in the class.
### Step 1: Listing the Heights
The given heights (in cm) of students are:
[tex]\[ 155, 161, 145, 149, 150, 145, 152, 145, 140 \][/tex]
### Step 2: Counting the Number of Students
To determine the number of students, we count the heights listed:
[tex]\[ \text{Total number of students} = 9 \][/tex]
### Step 3: Calculating the Mean Height
The mean (average) height is calculated by summing all the heights and then dividing by the number of students.
#### Sum of Heights:
[tex]\[ 155 + 161 + 145 + 149 + 150 + 145 + 152 + 145 + 140 = 1242 \][/tex]
#### Calculating the Mean:
[tex]\[ \text{Mean height} = \frac{\text{Sum of heights}}{\text{Number of students}} \][/tex]
[tex]\[ \text{Mean height} = \frac{1242}{9} \approx 149.11 \, \text{cm} \][/tex]
### Summary of Results:
- Number of students: 9
- Mean height: 149.11 cm
These values indicate that there are 9 students in the class, and the mean height of the students is approximately 149.11 cm.
