Home / 384.35-530.40-209.70

Finding the Fourth Proportional to 384.35, 530.40 and 209.70

Calculator

Solution

The fourth proportional to 384.35, 530.40 and 209.70 is: 289.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    384.35 : 530.40 = 209.70 : x
  2. Step 2: Convert to fraction form
    384.35/530.40 = 209.70/x
  3. Step 3: Cross multiply
    384.35x = 530.40 × 209.70
  4. Step 4: Simplify right side
    384.35x = 111,224.88
  5. Step 5: Solve for x
    x = 111,224.88/384.35
  6. Step 6: Final answer
    x = 289.39

Related Problems

Find fourth proportional to 192.17, 265.20 and 104.85
Half scale
Find fourth proportional to 768.69, 1,060.80 and 419.40
Double scale
Find fourth proportional to 385.35, 531.78 and 210.70
Similar ratio
Find fourth proportional to 576.52, 795.60 and 314.55
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.