What approximate value should come in the place of questions (?) mark.
`28.03 xx ? + 12.99% "of 1999.98" = (21.91)^(2)`

Options

A. 12
B. 6
C. 8
D. 4

Answer

To solve the equation \( 28.03 \times ? + 12.99\% \text{ of } 1999.98 = (21.91)^2 \), we will approximate the values and simplify the equation step by step.

### Step 1: Approximate the values
- Approximate \( 28.03 \) to \( 28 \).
- Approximate \( 12.99\% \) to \( 13\% \).
- Approximate \( 1999.98 \) to \( 2000 \).
- Approximate \( 21.91 \) to \( 22 \).

### Step 2: Rewrite the equation with approximations
The equation becomes:
\[ 28 \times ? + 13\% \text{ of } 2000 = 22^2 \]

### Step 3: Calculate \( 22^2 \)
\[ 22^2 = 484 \]

### Step 4: Calculate \( 13\% \text{ of } 2000 \)
To find \( 13\% \) of \( 2000 \):
\[ 13\% \text{ of } 2000 = \frac{13}{100} \times 2000 = 260 \]

### Step 5: Substitute back into the equation
Now substitute \( 260 \) back into the equation:
\[ 28 \times ? + 260 = 484 \]

### Step 6: Isolate the term with the question mark
Subtract \( 260 \) from both sides:
\[ 28 \times ? = 484 - 260 \]
\[ 28 \times ? = 224 \]

### Step 7: Solve for the question mark
Divide both sides by \( 28 \):
\[ ? = \frac{224}{28} \]
\[ ? = 8 \]

### Final Answer
The approximate value that should come in place of the question mark is \( 8 \).

---