Home / 9.75-21

Finding the Third Proportional to 9.75 and 21

Calculator

Solution

The third proportional to 9.75 and 21 is: 45.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.75 : 21 = 21 : x
  2. Step 2: Convert to fraction form
    9.75/21 = 21/x
  3. Step 3: Cross multiply
    9.75x = 21 × 21
  4. Step 4: Simplify right side
    9.75x = 441
  5. Step 5: Solve for x
    x = 441/9.75
  6. Step 6: Final answer
    x = 45.23

Related Problems

Find third proportional to 4.88 and 10.50
Half scale
Find third proportional to 19.50 and 42
Double scale
Find third proportional to 12 and 25
Similar ratio
Find third proportional to 14.63 and 31.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.15) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.