Analyzing Student Performance Data

The problem provides a table showing the marks obtained by four students (W, X, Y, Z) in four subjects (P, C, B, M). The maximum marks for each subject are 100. We need to calculate the average marks of the four students specifically in subjects P and C combined, rounded to one decimal place.

The table data is as follows:

Calculating Combined Marks for P and C per Student

To find the average marks of the four students in P and C together, we first need to find the combined marks in subjects P and C for each student.

• Student W: Marks in P + Marks in C = $70 + 90 = 160$
• Student X: Marks in P + Marks in C = $55 + 80 = 135$
• Student Y: Marks in P + Marks in C = $60 + 20 = 80$
• Student Z: Marks in P + Marks in C = $90 + 80 = 170$

Calculating the Total Combined Marks

Next, we sum the combined marks for all four students:

Total combined marks = (W's P+C) + (X's P+C) + (Y's P+C) + (Z's P+C)

Total combined marks = $160 + 135 + 80 + 170 = 545$

Calculating the Average Marks

The average marks of the four students in P and C together is the total combined marks divided by the number of students.

Number of students = 4

Average marks = $\frac{\text{Total combined marks}}{\text{Number of students}}$

Average marks = $\frac{545}{4}$

Let's perform the division:

$\frac{545}{4} = 136.25$

Rounding to One Decimal Place

The question asks for the average marks rounded to one decimal place. The calculated average is 136.25.

Rounding 136.25 to one decimal place gives 136.2.

Therefore, the average marks of the four students in P and C together, rounded to one decimal place, is 136.2.

Revision Table: Key Calculations

Average $= \frac{\text{Sum of Combined P+C Marks}}{\text{Number of Students}} = \frac{545}{4} = 136.25$

Rounded to one decimal place = 136.2

Additional Information: Understanding Averages

An average, or arithmetic mean, is a central value of a set of numbers. It is calculated by summing all the numbers in the set and then dividing by the count of numbers in the set. In this problem, we calculated the average of the combined scores (P+C) for each student.

Different types of averages exist, such as median and mode, but the term "average" in general usually refers to the arithmetic mean.

Rounding rules are important when precision is required. To round a number to one decimal place, you look at the digit in the second decimal place. If it is 5 or greater, you round up the first decimal place. If it is less than 5, the first decimal place remains as it is. In our calculation, 136.25 has 5 in the second decimal place.