A student obtained the following marks per centage in an examination English - 50, Accounts - 75, Economics - 60, B Std.-80, Hindi - 55. If weights are 2, 3, 3, 2, 1, respectively allotted to the subjects, his weighted mean is

Options

A. `(50 +75 + 60+80 + 55)/( 2+3+3+2+1)`
B. `((50 xx 2) + (75 xx 3) + (60 xx 3) + (80 xx 2) + (55 xx 1))/5`
C. `(50 xx 2 + 75 xx 3 + 60 xx 3 + 80 xx + 55 xx 1 )/(2 + 3 + 3 + 2 + 1 )`
D. none

Answer

To find the weighted mean of the student's marks, we will follow these steps:

### Step 1: List the Marks and Weights
We have the following marks and their corresponding weights:

- English: Marks = 50, Weight = 2
- Accounts: Marks = 75, Weight = 3
- Economics: Marks = 60, Weight = 3
- B Std.: Marks = 80, Weight = 2
- Hindi: Marks = 55, Weight = 1

### Step 2: Calculate the Weighted Marks
Next, we will multiply each subject's marks by its corresponding weight:

- Weighted Marks for English = 50 × 2 = 100
- Weighted Marks for Accounts = 75 × 3 = 225
- Weighted Marks for Economics = 60 × 3 = 180
- Weighted Marks for B Std. = 80 × 2 = 160
- Weighted Marks for Hindi = 55 × 1 = 55

### Step 3: Sum of Weighted Marks
Now, we will sum all the weighted marks calculated in the previous step:

Total Weighted Marks = 100 + 225 + 180 + 160 + 55 = 720

### Step 4: Sum of Weights
Next, we will sum the weights:

Total Weights = 2 + 3 + 3 + 2 + 1 = 11

### Step 5: Calculate the Weighted Mean
Finally, we will calculate the weighted mean using the formula:

\[ \text{Weighted Mean} = \frac{\text{Total Weighted Marks}}{\text{Total Weights}} = \frac{720}{11} \approx 65.45 \]

Thus, the weighted mean of the student's marks is approximately **65.45**.

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