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Finding the Fourth Proportional to 860.42, 1,187.31 and 487.42

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Solution

The fourth proportional to 860.42, 1,187.31 and 487.42 is: 672.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.42 : 1,187.31 = 487.42 : x
  2. Step 2: Convert to fraction form
    860.42/1,187.31 = 487.42/x
  3. Step 3: Cross multiply
    860.42x = 1,187.31 × 487.42
  4. Step 4: Simplify right side
    860.42x = 578,718.64
  5. Step 5: Solve for x
    x = 578,718.64/860.42
  6. Step 6: Final answer
    x = 672.60

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1.5x scale

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.