Home / 265.21-398.05-128.45

Finding the Fourth Proportional to 265.21, 398.05 and 128.45

Calculator

Solution

The fourth proportional to 265.21, 398.05 and 128.45 is: 192.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    265.21 : 398.05 = 128.45 : x
  2. Step 2: Convert to fraction form
    265.21/398.05 = 128.45/x
  3. Step 3: Cross multiply
    265.21x = 398.05 × 128.45
  4. Step 4: Simplify right side
    265.21x = 51,130.20
  5. Step 5: Solve for x
    x = 51,130.20/265.21
  6. Step 6: Final answer
    x = 192.79

Related Problems

Find fourth proportional to 132.60, 199.02 and 64.23
Half scale
Find fourth proportional to 530.42, 796.10 and 256.91
Double scale
Find fourth proportional to 266.21, 399.55 and 129.45
Similar ratio
Find fourth proportional to 397.81, 597.07 and 192.68
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.