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Finding the Fourth Proportional to 661.50, 991.53 and 417.87

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Solution

The fourth proportional to 661.50, 991.53 and 417.87 is: 626.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.50 : 991.53 = 417.87 : x
  2. Step 2: Convert to fraction form
    661.50/991.53 = 417.87/x
  3. Step 3: Cross multiply
    661.50x = 991.53 × 417.87
  4. Step 4: Simplify right side
    661.50x = 414,330.64
  5. Step 5: Solve for x
    x = 414,330.64/661.50
  6. Step 6: Final answer
    x = 626.35

Related Problems

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Half scale
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Double scale
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Similar ratio
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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.