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Finding the Fourth Proportional to 495.10, 683.40 and 390.21

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Solution

The fourth proportional to 495.10, 683.40 and 390.21 is: 538.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    495.10 : 683.40 = 390.21 : x
  2. Step 2: Convert to fraction form
    495.10/683.40 = 390.21/x
  3. Step 3: Cross multiply
    495.10x = 683.40 × 390.21
  4. Step 4: Simplify right side
    495.10x = 266,669.51
  5. Step 5: Solve for x
    x = 266,669.51/495.10
  6. Step 6: Final answer
    x = 538.62

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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.