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Finding the Fourth Proportional to 910.72, 1,256.78 and 512.40

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Solution

The fourth proportional to 910.72, 1,256.78 and 512.40 is: 707.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    910.72 : 1,256.78 = 512.40 : x
  2. Step 2: Convert to fraction form
    910.72/1,256.78 = 512.40/x
  3. Step 3: Cross multiply
    910.72x = 1,256.78 × 512.40
  4. Step 4: Simplify right side
    910.72x = 643,980.07
  5. Step 5: Solve for x
    x = 643,980.07/910.72
  6. Step 6: Final answer
    x = 707.11

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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.