Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    2
    ReputationRep:
    Stupid question,but I can t get my head round this .
    See attached doc.
    I do not understand how people know which value to divide by.

    Calculations: 420-30 : 390
    Then you have to divide it by 30 to get the right answer,but why 30 and not 420 & multiply by 100% to get percentage?
    Is it that you always have to work from the left to the right,surely there is a better explanation?
    There is no original value & no change in time,so those formulas don t work.
    Attached Files
  1. File Type: docxCalculating increased risk (% increase).docx (74.7 KB, 676 views)
    Offline

    2
    ReputationRep:
    (Original post by hissyfit)

    Calculations: 420-30 : 390
    Then you have to divide it by 30 to get the right answer,but why 30 and not 420 & multiply by 100% to get percentage?
    Is it that you always have to work from the left to the right,surely there is a better explanation?
    Because you want to work out how much greater risk a 75 yr old is at compared to 18-44yr old so you find the difference (390 for every 1000 people) and then you want to know how much greater this difference is compared to the 18-44 value.
    (i.e. how many times does 30 go into 390 or how many more times at risk is a 75yr old person).

    Does that make sense? :-)
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Did TEF Bronze Award affect your UCAS choices?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.