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Finding the Fourth Proportional to 145.47, 218.51 and 91.40

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Solution

The fourth proportional to 145.47, 218.51 and 91.40 is: 137.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.47 : 218.51 = 91.40 : x
  2. Step 2: Convert to fraction form
    145.47/218.51 = 91.40/x
  3. Step 3: Cross multiply
    145.47x = 218.51 × 91.40
  4. Step 4: Simplify right side
    145.47x = 19,972.35
  5. Step 5: Solve for x
    x = 19,972.35/145.47
  6. Step 6: Final answer
    x = 137.30

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.