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Finding the Fourth Proportional to 420.48, 577.44 and 390.42

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Solution

The fourth proportional to 420.48, 577.44 and 390.42 is: 536.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.48 : 577.44 = 390.42 : x
  2. Step 2: Convert to fraction form
    420.48/577.44 = 390.42/x
  3. Step 3: Cross multiply
    420.48x = 577.44 × 390.42
  4. Step 4: Simplify right side
    420.48x = 225,444.12
  5. Step 5: Solve for x
    x = 225,444.12/420.48
  6. Step 6: Final answer
    x = 536.16

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.