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Finding the Fourth Proportional to 623.28, 859.80 and 390.36

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Solution

The fourth proportional to 623.28, 859.80 and 390.36 is: 538.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    623.28 : 859.80 = 390.36 : x
  2. Step 2: Convert to fraction form
    623.28/859.80 = 390.36/x
  3. Step 3: Cross multiply
    623.28x = 859.80 × 390.36
  4. Step 4: Simplify right side
    623.28x = 335,631.53
  5. Step 5: Solve for x
    x = 335,631.53/623.28
  6. Step 6: Final answer
    x = 538.49

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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.