PP-T1-PS121

[max999]

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, how many of the 12 listed amounts are within 1.5 standard deviations of the mean?

(A) Four
(B) Six
(C) Nine
(D) Ten
(E) Eleven

ANSWER: (E)

[max999]

自己頂ㄧ下
麻煩大大了

[Huang Hsin-Yi]

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, how many of the 12 listed amounts are within 1.5 standard deviations of the mean?
(A) Four
(B) Six
(C) Nine
(D) Ten
(E) Eleven

ANSWER: (E)

問12個數 那些在平均數的1.5個標準差內
所以 找出 8.1+0.3*1.5-------8.1-0.3*1.5---->8.55-----7.65間的數即可

沒看到你那12個數,不知道我說的對不對