Home / 357-428

Finding the Third Proportional to 357 and 428

Calculator

Solution

The third proportional to 357 and 428 is: 513.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    357 : 428 = 428 : x
  2. Step 2: Convert to fraction form
    357/428 = 428/x
  3. Step 3: Cross multiply
    357x = 428 × 428
  4. Step 4: Simplify right side
    357x = 183,184
  5. Step 5: Solve for x
    x = 183,184/357
  6. Step 6: Final answer
    x = 513.12

Related Problems

Find third proportional to 178.50 and 214
Half scale
Find third proportional to 714 and 856
Double scale
Find third proportional to 359 and 430
Similar ratio
Find third proportional to 535.50 and 642
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.