Home / 631.85-871.93-398.75

Finding the Fourth Proportional to 631.85, 871.93 and 398.75

Calculator

Solution

The fourth proportional to 631.85, 871.93 and 398.75 is: 550.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.85 : 871.93 = 398.75 : x
  2. Step 2: Convert to fraction form
    631.85/871.93 = 398.75/x
  3. Step 3: Cross multiply
    631.85x = 871.93 × 398.75
  4. Step 4: Simplify right side
    631.85x = 347,682.09
  5. Step 5: Solve for x
    x = 347,682.09/631.85
  6. Step 6: Final answer
    x = 550.26

Related Problems

Find fourth proportional to 315.93, 435.97 and 199.38
Half scale
Find fourth proportional to 1,263.70, 1,743.86 and 797.50
Double scale
Find fourth proportional to 632.85, 873.31 and 399.75
Similar ratio
Find fourth proportional to 947.78, 1,307.90 and 598.13
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.