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Finding the Fourth Proportional to 919.17, 1,378.76 and 646.48

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Solution

The fourth proportional to 919.17, 1,378.76 and 646.48 is: 969.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.17 : 1,378.76 = 646.48 : x
  2. Step 2: Convert to fraction form
    919.17/1,378.76 = 646.48/x
  3. Step 3: Cross multiply
    919.17x = 1,378.76 × 646.48
  4. Step 4: Simplify right side
    919.17x = 891,339.26
  5. Step 5: Solve for x
    x = 891,339.26/919.17
  6. Step 6: Final answer
    x = 969.72

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.