Home / 155.34-214.14-128.79

Finding the Fourth Proportional to 155.34, 214.14 and 128.79

Calculator

Solution

The fourth proportional to 155.34, 214.14 and 128.79 is: 177.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.34 : 214.14 = 128.79 : x
  2. Step 2: Convert to fraction form
    155.34/214.14 = 128.79/x
  3. Step 3: Cross multiply
    155.34x = 214.14 × 128.79
  4. Step 4: Simplify right side
    155.34x = 27,579.09
  5. Step 5: Solve for x
    x = 27,579.09/155.34
  6. Step 6: Final answer
    x = 177.54

Related Problems

Find fourth proportional to 77.67, 107.07 and 64.40
Half scale
Find fourth proportional to 310.68, 428.28 and 257.58
Double scale
Find fourth proportional to 156.34, 215.52 and 129.79
Similar ratio
Find fourth proportional to 233.01, 321.21 and 193.19
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.