if 5 school books weigh an average of 800g, and 4 of them weigh 400g, 600g,800g, and 1000g respectively, the 5th book weighs

It appears that the books have a scale factor for each one, meaning that the 5th book would be 1200g.

To check this regarding the average weight, add the weight of all 5 books together and divide by 5.

(400 + 600 + 800 + 1000 + 1200) / 5 = 800

the fifth book weighs 1200g

Step-by-step explanation:

(400+600+800+1000+x)/5=800 =>

(2800+x)/5=800 =>

x=(800×5)-2800=>

x=4000-2800=>

x=1200

answer: 0.95, d

step-by-step explanation:

first, you have to combine the percentages of costumers ordering pizza or salad. 25% (percent of salads ordered) plus 70% (percent of pizzas ordered) is equal to 95%. then, turn 95% into a fraction: 95/100. lastly, divide 95 by 100 and you will get 0.95, d.