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Finding the Fourth Proportional to 491.65, 678.57 and 305.22

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Solution

The fourth proportional to 491.65, 678.57 and 305.22 is: 421.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.65 : 678.57 = 305.22 : x
  2. Step 2: Convert to fraction form
    491.65/678.57 = 305.22/x
  3. Step 3: Cross multiply
    491.65x = 678.57 × 305.22
  4. Step 4: Simplify right side
    491.65x = 207,113.14
  5. Step 5: Solve for x
    x = 207,113.14/491.65
  6. Step 6: Final answer
    x = 421.26

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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.