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Finding the Fourth Proportional to 21,210, 31,815 and 6,618

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Solution

The fourth proportional to 21,210, 31,815 and 6,618 is: 9,927

Step by Step Solution

  1. Step 1: Write the proportion equation
    21,210 : 31,815 = 6,618 : x
  2. Step 2: Convert to fraction form
    21,210/31,815 = 6,618/x
  3. Step 3: Cross multiply
    21,210x = 31,815 × 6,618
  4. Step 4: Simplify right side
    21,210x = 210,551,670
  5. Step 5: Solve for x
    x = 210,551,670/21,210
  6. Step 6: Final answer
    x = 9,927

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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.