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Finding the Fourth Proportional to 387.51, 534.72 and 221.70

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Solution

The fourth proportional to 387.51, 534.72 and 221.70 is: 305.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.51 : 534.72 = 221.70 : x
  2. Step 2: Convert to fraction form
    387.51/534.72 = 221.70/x
  3. Step 3: Cross multiply
    387.51x = 534.72 × 221.70
  4. Step 4: Simplify right side
    387.51x = 118,547.42
  5. Step 5: Solve for x
    x = 118,547.42/387.51
  6. Step 6: Final answer
    x = 305.92

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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.