Home / 311.64-428.99-256.29

Finding the Fourth Proportional to 311.64, 428.99 and 256.29

Calculator

Solution

The fourth proportional to 311.64, 428.99 and 256.29 is: 352.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.64 : 428.99 = 256.29 : x
  2. Step 2: Convert to fraction form
    311.64/428.99 = 256.29/x
  3. Step 3: Cross multiply
    311.64x = 428.99 × 256.29
  4. Step 4: Simplify right side
    311.64x = 109,945.85
  5. Step 5: Solve for x
    x = 109,945.85/311.64
  6. Step 6: Final answer
    x = 352.80

Related Problems

Find fourth proportional to 155.82, 214.50 and 128.15
Half scale
Find fourth proportional to 623.28, 857.98 and 512.58
Double scale
Find fourth proportional to 312.64, 430.37 and 257.29
Similar ratio
Find fourth proportional to 467.46, 643.49 and 384.44
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.