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Finding the Fourth Proportional to 786.76, 1,085.62 and 455.20

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Solution

The fourth proportional to 786.76, 1,085.62 and 455.20 is: 628.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.76 : 1,085.62 = 455.20 : x
  2. Step 2: Convert to fraction form
    786.76/1,085.62 = 455.20/x
  3. Step 3: Cross multiply
    786.76x = 1,085.62 × 455.20
  4. Step 4: Simplify right side
    786.76x = 494,174.22
  5. Step 5: Solve for x
    x = 494,174.22/786.76
  6. Step 6: Final answer
    x = 628.11

Related Problems

Find fourth proportional to 393.38, 542.81 and 227.60
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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.