Home / 657.70-987-438.58

Finding the Fourth Proportional to 657.70, 987 and 438.58

Calculator

Solution

The fourth proportional to 657.70, 987 and 438.58 is: 658.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.70 : 987 = 438.58 : x
  2. Step 2: Convert to fraction form
    657.70/987 = 438.58/x
  3. Step 3: Cross multiply
    657.70x = 987 × 438.58
  4. Step 4: Simplify right side
    657.70x = 432,878.46
  5. Step 5: Solve for x
    x = 432,878.46/657.70
  6. Step 6: Final answer
    x = 658.17

Related Problems

Find fourth proportional to 328.85, 493.50 and 219.29
Half scale
Find fourth proportional to 1,315.40, 1,974 and 877.16
Double scale
Find fourth proportional to 658.70, 988.50 and 439.58
Similar ratio
Find fourth proportional to 986.55, 1,480.50 and 657.87
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.