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Finding the Fourth Proportional to 678.79, 1,017.37 and 313.48

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Solution

The fourth proportional to 678.79, 1,017.37 and 313.48 is: 469.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.79 : 1,017.37 = 313.48 : x
  2. Step 2: Convert to fraction form
    678.79/1,017.37 = 313.48/x
  3. Step 3: Cross multiply
    678.79x = 1,017.37 × 313.48
  4. Step 4: Simplify right side
    678.79x = 318,925.15
  5. Step 5: Solve for x
    x = 318,925.15/678.79
  6. Step 6: Final answer
    x = 469.84

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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.