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Finding the Fourth Proportional to 718.75, 991.63 and 438.88

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Solution

The fourth proportional to 718.75, 991.63 and 438.88 is: 605.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.75 : 991.63 = 438.88 : x
  2. Step 2: Convert to fraction form
    718.75/991.63 = 438.88/x
  3. Step 3: Cross multiply
    718.75x = 991.63 × 438.88
  4. Step 4: Simplify right side
    718.75x = 435,206.57
  5. Step 5: Solve for x
    x = 435,206.57/718.75
  6. Step 6: Final answer
    x = 605.50

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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.