Using Worksheet to answer Question 8-47 step by step 

Yea it's too complicated . Where did you get the 5 ?? 97/5 ??

Where did u get th “5” ???

+MichaelJamie Morley His way is cleaner and provides you with a place for each calculation, but I find it easier to just find the difference between the two pressure alts and divide by ten to get a value for each hundredth. Then figure out how many hundredths I need to get my answer. eg. 28.22 is 2 hundredths. so I would multiply 9.7 twice to get 19.4. Write down your 28.22 Figure the difference between 28.20 and 28.30 (1,630 - 1,533) = 97feet 97/10 (the difference between .20 and .30) = 9.7 feet for each 10th hg so we need to find 28.22 so multiply 9.7' twice = 19.4' subtract 19.4 from the first figure of 1630 = 1610.6 add that to your indicated altitude of 1380 = 2990.6' rounded to 2991'. The difference between 28.20 and 28.30 is 97 feet. (1630 - 1533 = 97) The difference between 28.30 and 28.20 is 10 divide 97' by 10 and you get 9.7 per 1/100 hg The difference between 28.20 and 28.22 is .02 So you need the value of 2 one-hundredths more than 28.20 so 9.7 x 2 = 19.4' Now we subtract 19.4 from the figure given in 28.20 which is 1630 and we get 1610.6' We then add 1610.6 to our indicated altitude of 1380 and we get 2990.6 or 2991 rounded up.