Home / 657.90-907.90-378.20

Finding the Fourth Proportional to 657.90, 907.90 and 378.20

Calculator

Solution

The fourth proportional to 657.90, 907.90 and 378.20 is: 521.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.90 : 907.90 = 378.20 : x
  2. Step 2: Convert to fraction form
    657.90/907.90 = 378.20/x
  3. Step 3: Cross multiply
    657.90x = 907.90 × 378.20
  4. Step 4: Simplify right side
    657.90x = 343,369.10
  5. Step 5: Solve for x
    x = 343,369.10/657.90
  6. Step 6: Final answer
    x = 521.92

Related Problems

Find fourth proportional to 328.95, 453.95 and 189.10
Half scale
Find fourth proportional to 1,315.80, 1,815.80 and 756.41
Double scale
Find fourth proportional to 658.90, 909.28 and 379.20
Similar ratio
Find fourth proportional to 986.85, 1,361.85 and 567.30
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.