Home / 506.84-698.40-388.80

Finding the Fourth Proportional to 506.84, 698.40 and 388.80

Calculator

Solution

The fourth proportional to 506.84, 698.40 and 388.80 is: 535.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    506.84 : 698.40 = 388.80 : x
  2. Step 2: Convert to fraction form
    506.84/698.40 = 388.80/x
  3. Step 3: Cross multiply
    506.84x = 698.40 × 388.80
  4. Step 4: Simplify right side
    506.84x = 271,537.92
  5. Step 5: Solve for x
    x = 271,537.92/506.84
  6. Step 6: Final answer
    x = 535.75

Related Problems

Find fourth proportional to 253.42, 349.20 and 194.40
Half scale
Find fourth proportional to 1,013.67, 1,396.80 and 777.60
Double scale
Find fourth proportional to 507.84, 699.78 and 389.80
Similar ratio
Find fourth proportional to 760.25, 1,047.60 and 583.20
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.