Find the value of x in each of the following, so that the numbers are in proportion.
`9, 21, 33, x`

Answer

To find the value of \( x \) so that the numbers \( 9, 21, 33, x \) are in proportion, we can follow these steps:

### Step 1: Understand the Proportion
When four numbers \( a, b, c, d \) are in proportion, it means that:
\[ \frac{a}{b} = \frac{c}{d} \]
In our case, we have:
\[ \frac{9}{21} = \frac{33}{x} \]

### Step 2: Set Up the Equation
From the proportion, we can set up the equation:
\[ \frac{9}{21} = \frac{33}{x} \]

### Step 3: Cross Multiply
To eliminate the fractions, we cross multiply:
\[ 9 \cdot x = 21 \cdot 33 \]

### Step 4: Calculate \( 21 \cdot 33 \)
Now we calculate \( 21 \cdot 33 \):
\[ 21 \cdot 33 = 693 \]
So, we have:
\[ 9x = 693 \]

### Step 5: Solve for \( x \)
Now, we divide both sides by 9 to find \( x \):
\[ x = \frac{693}{9} \]

### Step 6: Calculate \( \frac{693}{9} \)
Now, we perform the division:
\[ 693 \div 9 = 77 \]
Thus, \( x = 77 \).

### Final Answer
The value of \( x \) is \( 77 \).

---