The teachers at a middle school counted how many computers they had in their classrooms.

Question

Computers in classrooms
Teacher Number of computers
Mr. Schmidt
five tally marks two tally marks
Miss Murphy
three tally marks
Mr. Morales
two tally marks
Mr. Lim
five tally marks three tally marks
Mr. Watson
five tally marks five tally marks

What is the mean of the numbers?

Answer 1

To find the mean number of computers, we first need to convert the tally marks into numerical values for each teacher.

Mr. Schmidt:

• Five tally marks: 5
• Two tally marks: 2
• Total for Mr. Schmidt: 5 + 2 = 7

Miss Murphy:

• Three tally marks: 3
• Total for Miss Murphy: 3

Mr. Morales:

• Two tally marks: 2
• Total for Mr. Morales: 2

Mr. Lim:

• Five tally marks: 5
• Three tally marks: 3
• Total for Mr. Lim: 5 + 3 = 8

Mr. Watson:

• Five tally marks: 5
• Five tally marks: 5
• Total for Mr. Watson: 5 + 5 = 10

Now, let's summarize the total number of computers for each teacher:

• Mr. Schmidt: 7
• Miss Murphy: 3
• Mr. Morales: 2
• Mr. Lim: 8
• Mr. Watson: 10

Next, we calculate the total number of computers by adding these values together: \[ 7 + 3 + 2 + 8 + 10 = 30 \]

Now, we count the number of teachers:

• There are 5 teachers in total.

To find the mean, we divide the total number of computers by the number of teachers: \[ \text{Mean} = \frac{\text{Total number of computers}}{\text{Number of teachers}} = \frac{30}{5} = 6 \]

Therefore, the mean number of computers per teacher is 6.