Complete Question 
In your biology class, your final  grade is based on several things: a lab score, scores on two major tests, and your score on the final exam. There are 100 points available for each score. However, the lab score is worth 25% of your total grade, each major test is worth 22:5%, and the final exam is worth 30%. Compute the weighted average for the following scores: 92 on the lab, 81 on the first major test, 93 on the second major test, and 85 on the final exam. (Enter your answer to one decimal place)
Answer:
The weighted average is   
 
Step-by-step explanation:
From the question we are told that 
   The worth of the lab score is  25% of total grade
   The worth of each major  test is   22.5% of total grade
    The worth of final exam is  30% of total grade
The  score on lab is  92
The score on first major test 81 
The score on second major test 93
  The score on final  exam is  85
Generally the weighted score is mathematically represented as 
      
=> 
=> 