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Finding the Fourth Proportional to 53.40, 79.76 and 47.40

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Solution

The fourth proportional to 53.40, 79.76 and 47.40 is: 70.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    53.40 : 79.76 = 47.40 : x
  2. Step 2: Convert to fraction form
    53.40/79.76 = 47.40/x
  3. Step 3: Cross multiply
    53.40x = 79.76 × 47.40
  4. Step 4: Simplify right side
    53.40x = 3,780.62
  5. Step 5: Solve for x
    x = 3,780.62/53.40
  6. Step 6: Final answer
    x = 70.80

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.