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Finding the Fourth Proportional to 678.53, 1,017.80 and 191.63

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Solution

The fourth proportional to 678.53, 1,017.80 and 191.63 is: 287.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.53 : 1,017.80 = 191.63 : x
  2. Step 2: Convert to fraction form
    678.53/1,017.80 = 191.63/x
  3. Step 3: Cross multiply
    678.53x = 1,017.80 × 191.63
  4. Step 4: Simplify right side
    678.53x = 195,041.01
  5. Step 5: Solve for x
    x = 195,041.01/678.53
  6. Step 6: Final answer
    x = 287.45

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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.