Home / 428.98-643.29

Finding the Third Proportional to 428.98 and 643.29

Calculator

Solution

The third proportional to 428.98 and 643.29 is: 964.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.98 : 643.29 = 643.29 : x
  2. Step 2: Convert to fraction form
    428.98/643.29 = 643.29/x
  3. Step 3: Cross multiply
    428.98x = 643.29 × 643.29
  4. Step 4: Simplify right side
    428.98x = 413,820.82
  5. Step 5: Solve for x
    x = 413,820.82/428.98
  6. Step 6: Final answer
    x = 964.67

Related Problems

Find third proportional to 214.49 and 321.64
Half scale
Find third proportional to 857.95 and 1,286.58
Double scale
Find third proportional to 431 and 646
Similar ratio
Find third proportional to 643.46 and 964.93
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.