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Finding the Fourth Proportional to 1,185.80, 1,636.20 and 688.35

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Solution

The fourth proportional to 1,185.80, 1,636.20 and 688.35 is: 949.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,185.80 : 1,636.20 = 688.35 : x
  2. Step 2: Convert to fraction form
    1,185.80/1,636.20 = 688.35/x
  3. Step 3: Cross multiply
    1,185.80x = 1,636.20 × 688.35
  4. Step 4: Simplify right side
    1,185.80x = 1,126,278.27
  5. Step 5: Solve for x
    x = 1,126,278.27/1,185.80
  6. Step 6: Final answer
    x = 949.81

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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.