Home / 455.70-628.38-289.78

Finding the Fourth Proportional to 455.70, 628.38 and 289.78

Calculator

Solution

The fourth proportional to 455.70, 628.38 and 289.78 is: 399.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    455.70 : 628.38 = 289.78 : x
  2. Step 2: Convert to fraction form
    455.70/628.38 = 289.78/x
  3. Step 3: Cross multiply
    455.70x = 628.38 × 289.78
  4. Step 4: Simplify right side
    455.70x = 182,091.20
  5. Step 5: Solve for x
    x = 182,091.20/455.70
  6. Step 6: Final answer
    x = 399.58

Related Problems

Find fourth proportional to 227.85, 314.19 and 144.89
Half scale
Find fourth proportional to 911.40, 1,256.77 and 579.56
Double scale
Find fourth proportional to 456.70, 629.76 and 290.78
Similar ratio
Find fourth proportional to 683.55, 942.57 and 434.67
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.