An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (1)
Calculate the total number of pens: ( 0 × 4 ) + ( 1 × 6 ) + ( 2 × 7 ) + ( 3 × 5 ) + ( 4 × 3 ) + ( 5 × 1 ) = 52 .
Identify the modal number of pens by finding the highest frequency in the table, which is 7 pupils with 2 pens.
The total number of pens is 52 .
The modal number of pens is 2 .
Explanation
Understand the problem We are given a table that shows the number of pupils who have a certain number of pens in their pencil case. Our goal is to find the total number of pens in the classroom and the modal number of pens in a pencil case.
Plan to find the total number of pens To find the total number of pens, we need to multiply the number of pens by the number of pupils who have that many pens, and then sum the results.
Calculate the total number of pens The number of pens are: 0, 1, 2, 3, 4, 5. The corresponding number of pupils are: 4, 6, 7, 5, 3, 1. So, the total number of pens is: ( 0 × 4 ) + ( 1 × 6 ) + ( 2 × 7 ) + ( 3 × 5 ) + ( 4 × 3 ) + ( 5 × 1 ) = 0 + 6 + 14 + 15 + 12 + 5 = 52 Therefore, the total number of pens in the classroom is 52.
Plan to find the modal number of pens To find the modal number of pens, we need to find the number of pens that occurs most frequently. This is the number of pens that corresponds to the largest number of pupils.
Find the modal number of pens Looking at the table, we see that the largest number of pupils is 7, which corresponds to 2 pens. Therefore, the modal number of pens in a pencil case is 2.
State the final answer a) The total number of pens in the classroom is 52. b) The modal number of pens in a pencil case is 2.
Examples
Understanding data distributions, like the number of pens students carry, helps in resource allocation. For example, schools can use this data to estimate the number of pens needed for exams or to understand student preparedness. This type of analysis is also used in business to understand customer behavior and optimize inventory.
