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Finding the Fourth Proportional to 912.45, 1,256.83 and 646.43

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Solution

The fourth proportional to 912.45, 1,256.83 and 646.43 is: 890.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.45 : 1,256.83 = 646.43 : x
  2. Step 2: Convert to fraction form
    912.45/1,256.83 = 646.43/x
  3. Step 3: Cross multiply
    912.45x = 1,256.83 × 646.43
  4. Step 4: Simplify right side
    912.45x = 812,452.62
  5. Step 5: Solve for x
    x = 812,452.62/912.45
  6. Step 6: Final answer
    x = 890.41

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.