Home / 1,990-2,985.72-622

Finding the Fourth Proportional to 1,990, 2,985.72 and 622

Calculator

Solution

The fourth proportional to 1,990, 2,985.72 and 622 is: 933.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,990 : 2,985.72 = 622 : x
  2. Step 2: Convert to fraction form
    1,990/2,985.72 = 622/x
  3. Step 3: Cross multiply
    1,990x = 2,985.72 × 622
  4. Step 4: Simplify right side
    1,990x = 1,857,117.84
  5. Step 5: Solve for x
    x = 1,857,117.84/1,990
  6. Step 6: Final answer
    x = 933.23

Related Problems

Find fourth proportional to 995, 1,492.86 and 311
Half scale
Find fourth proportional to 3,980, 5,971.44 and 1,244
Double scale
Find fourth proportional to 1,991, 2,987.22 and 623
Similar ratio
Find fourth proportional to 2,985, 4,478.58 and 933
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.