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Finding the Fourth Proportional to 620.42, 856 and 384.40

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Solution

The fourth proportional to 620.42, 856 and 384.40 is: 530.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.42 : 856 = 384.40 : x
  2. Step 2: Convert to fraction form
    620.42/856 = 384.40/x
  3. Step 3: Cross multiply
    620.42x = 856 × 384.40
  4. Step 4: Simplify right side
    620.42x = 329,046.40
  5. Step 5: Solve for x
    x = 329,046.40/620.42
  6. Step 6: Final answer
    x = 530.36

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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.