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Finding the Fourth Proportional to 145.40, 218.08 and 42.70

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Solution

The fourth proportional to 145.40, 218.08 and 42.70 is: 64.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.40 : 218.08 = 42.70 : x
  2. Step 2: Convert to fraction form
    145.40/218.08 = 42.70/x
  3. Step 3: Cross multiply
    145.40x = 218.08 × 42.70
  4. Step 4: Simplify right side
    145.40x = 9,312.02
  5. Step 5: Solve for x
    x = 9,312.02/145.40
  6. Step 6: Final answer
    x = 64.04

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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.