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Finding the Fourth Proportional to 646.31, 891.95 and 380.77

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Solution

The fourth proportional to 646.31, 891.95 and 380.77 is: 525.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.31 : 891.95 = 380.77 : x
  2. Step 2: Convert to fraction form
    646.31/891.95 = 380.77/x
  3. Step 3: Cross multiply
    646.31x = 891.95 × 380.77
  4. Step 4: Simplify right side
    646.31x = 339,623.67
  5. Step 5: Solve for x
    x = 339,623.67/646.31
  6. Step 6: Final answer
    x = 525.48

Related Problems

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Half scale
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Double scale
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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.