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Finding the Fourth Proportional to 860.77, 1,187.80 and 487.78

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Solution

The fourth proportional to 860.77, 1,187.80 and 487.78 is: 673.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.77 : 1,187.80 = 487.78 : x
  2. Step 2: Convert to fraction form
    860.77/1,187.80 = 487.78/x
  3. Step 3: Cross multiply
    860.77x = 1,187.80 × 487.78
  4. Step 4: Simplify right side
    860.77x = 579,382.65
  5. Step 5: Solve for x
    x = 579,382.65/860.77
  6. Step 6: Final answer
    x = 673.10

Related Problems

Find fourth proportional to 430.38, 593.90 and 243.89
Half scale
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Double scale
Find fourth proportional to 861.77, 1,189.17 and 488.78
Similar ratio
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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.