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Finding the Fourth Proportional to 66.30, 91.40 and 53.20

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Solution

The fourth proportional to 66.30, 91.40 and 53.20 is: 73.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.30 : 91.40 = 53.20 : x
  2. Step 2: Convert to fraction form
    66.30/91.40 = 53.20/x
  3. Step 3: Cross multiply
    66.30x = 91.40 × 53.20
  4. Step 4: Simplify right side
    66.30x = 4,862.48
  5. Step 5: Solve for x
    x = 4,862.48/66.30
  6. Step 6: Final answer
    x = 73.34

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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.