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Finding the Fourth Proportional to 430.66, 645.78 and 142

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Solution

The fourth proportional to 430.66, 645.78 and 142 is: 212.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.66 : 645.78 = 142 : x
  2. Step 2: Convert to fraction form
    430.66/645.78 = 142/x
  3. Step 3: Cross multiply
    430.66x = 645.78 × 142
  4. Step 4: Simplify right side
    430.66x = 91,700.76
  5. Step 5: Solve for x
    x = 91,700.76/430.66
  6. Step 6: Final answer
    x = 212.93

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