Home / 870.55-1,305.72-315.20

Finding the Fourth Proportional to 870.55, 1,305.72 and 315.20

Calculator

Solution

The fourth proportional to 870.55, 1,305.72 and 315.20 is: 472.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.55 : 1,305.72 = 315.20 : x
  2. Step 2: Convert to fraction form
    870.55/1,305.72 = 315.20/x
  3. Step 3: Cross multiply
    870.55x = 1,305.72 × 315.20
  4. Step 4: Simplify right side
    870.55x = 411,566.21
  5. Step 5: Solve for x
    x = 411,566.21/870.55
  6. Step 6: Final answer
    x = 472.77

Related Problems

Find fourth proportional to 435.27, 652.86 and 157.60
Half scale
Find fourth proportional to 1,741.10, 2,611.44 and 630.41
Double scale
Find fourth proportional to 871.55, 1,307.22 and 316.20
Similar ratio
Find fourth proportional to 1,305.82, 1,958.58 and 472.80
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.