Home / 340.76-469.98-287.40

Finding the Fourth Proportional to 340.76, 469.98 and 287.40

Calculator

Solution

The fourth proportional to 340.76, 469.98 and 287.40 is: 396.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    340.76 : 469.98 = 287.40 : x
  2. Step 2: Convert to fraction form
    340.76/469.98 = 287.40/x
  3. Step 3: Cross multiply
    340.76x = 469.98 × 287.40
  4. Step 4: Simplify right side
    340.76x = 135,072.25
  5. Step 5: Solve for x
    x = 135,072.25/340.76
  6. Step 6: Final answer
    x = 396.39

Related Problems

Find fourth proportional to 170.38, 234.99 and 143.70
Half scale
Find fourth proportional to 681.52, 939.96 and 574.80
Double scale
Find fourth proportional to 341.76, 471.36 and 288.40
Similar ratio
Find fourth proportional to 511.14, 704.97 and 431.10
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.