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Finding the Fourth Proportional to 321, 443.78 and 307.40

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Solution

The fourth proportional to 321, 443.78 and 307.40 is: 424.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    321 : 443.78 = 307.40 : x
  2. Step 2: Convert to fraction form
    321/443.78 = 307.40/x
  3. Step 3: Cross multiply
    321x = 443.78 × 307.40
  4. Step 4: Simplify right side
    321x = 136,417.97
  5. Step 5: Solve for x
    x = 136,417.97/321
  6. Step 6: Final answer
    x = 424.98

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.