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Finding the Fourth Proportional to 430.63, 646.31 and 199.78

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Solution

The fourth proportional to 430.63, 646.31 and 199.78 is: 299.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.63 : 646.31 = 199.78 : x
  2. Step 2: Convert to fraction form
    430.63/646.31 = 199.78/x
  3. Step 3: Cross multiply
    430.63x = 646.31 × 199.78
  4. Step 4: Simplify right side
    430.63x = 129,119.81
  5. Step 5: Solve for x
    x = 129,119.81/430.63
  6. Step 6: Final answer
    x = 299.84

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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.