Home / 677.17-938.75-640.21

Finding the Fourth Proportional to 677.17, 938.75 and 640.21

Calculator

Solution

The fourth proportional to 677.17, 938.75 and 640.21 is: 887.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.17 : 938.75 = 640.21 : x
  2. Step 2: Convert to fraction form
    677.17/938.75 = 640.21/x
  3. Step 3: Cross multiply
    677.17x = 938.75 × 640.21
  4. Step 4: Simplify right side
    677.17x = 600,997.14
  5. Step 5: Solve for x
    x = 600,997.14/677.17
  6. Step 6: Final answer
    x = 887.51

Related Problems

Find fourth proportional to 338.59, 469.38 and 320.11
Half scale
Find fourth proportional to 1,354.34, 1,877.50 and 1,280.42
Double scale
Find fourth proportional to 678.17, 940.14 and 641.21
Similar ratio
Find fourth proportional to 1,015.76, 1,408.13 and 960.32
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.