7.51 8.22 7.86 8.36
8.09 7.83 8.30 8.01
7.73 8.25 7.96 8.53
A vending machine is designed to dispense 8 ounces of coffee into a cup. After a test that recorded the number of ounces of coffee in each of 1,000 cups dispensed by the vending machine, the 12 listed amounts, in ounces, were selected from the data. If the 1,000 recorded amounts have a mean of 8.1 ounces and a standard deviation of 0.3 ounce,howmany of the 12 listed amounts are written 1.5 standard deviations of the mean?
four
six
nine
ten
eleven
Could someone please explain the rationale of solving this by using Z-score? For the experts out there, how much stats is on the real GMAT? I was quite taken aback that this question requires knowledge of z-score to solve. The s.d. chapter is pretty simple in OG, but are we going to end up using the t-test too?
Answer is 11
8.09 7.83 8.30 8.01
7.73 8.25 7.96 8.53
A vending machine is designed to dispense 8 ounces of coffee into a cup. After a test that recorded the number of ounces of coffee in each of 1,000 cups dispensed by the vending machine, the 12 listed amounts, in ounces, were selected from the data. If the 1,000 recorded amounts have a mean of 8.1 ounces and a standard deviation of 0.3 ounce,howmany of the 12 listed amounts are written 1.5 standard deviations of the mean?
four
six
nine
ten
eleven
Could someone please explain the rationale of solving this by using Z-score? For the experts out there, how much stats is on the real GMAT? I was quite taken aback that this question requires knowledge of z-score to solve. The s.d. chapter is pretty simple in OG, but are we going to end up using the t-test too?
Answer is 11
Last edited by OneTwoThreeFour on Fri Apr 15, 2011 1:43 pm, edited 1 time in total.
