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Finding the Fourth Proportional to 856.88, 1,178.57 and 690.71

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Solution

The fourth proportional to 856.88, 1,178.57 and 690.71 is: 950.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.88 : 1,178.57 = 690.71 : x
  2. Step 2: Convert to fraction form
    856.88/1,178.57 = 690.71/x
  3. Step 3: Cross multiply
    856.88x = 1,178.57 × 690.71
  4. Step 4: Simplify right side
    856.88x = 814,040.74
  5. Step 5: Solve for x
    x = 814,040.74/856.88
  6. Step 6: Final answer
    x = 950.01

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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.