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Finding the Fourth Proportional to 430.95, 646.42 and 257.67

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Solution

The fourth proportional to 430.95, 646.42 and 257.67 is: 386.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.95 : 646.42 = 257.67 : x
  2. Step 2: Convert to fraction form
    430.95/646.42 = 257.67/x
  3. Step 3: Cross multiply
    430.95x = 646.42 × 257.67
  4. Step 4: Simplify right side
    430.95x = 166,560.42
  5. Step 5: Solve for x
    x = 166,560.42/430.95
  6. Step 6: Final answer
    x = 386.50

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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.