Vending Machine - Std Dev

[karthikpandian19]

A vending m/c is designed to dispense 8 ounces of coffee per cup. After a test that recorded no of ounces of coffee in each of the 1000 cups dispensed by the vending m/c, the 12 listed amounts, in ounces, were selected for the data. if the 1000 recorded data have a mean of 8.1 ounces and standard deviation of 0.3, how many of the 12 listed amounts comes within 1.5 std dev of the mean?

7.51 8.09 7.73
8.22 7.83 8.25
7.86 8.30 7.96
8.36 8.01 8.53


Four
Six
Nine
Ten
Eleven

[Anurag@Gurome]

A vending m/c is designed to dispense 8 ounces of coffee per cup. After a test that recorded no of ounces of coffee in each of the 1000 cups dispensed by the vending m/c, the 12 listed amounts, in ounces, were selected for the data. if the 1000 recorded data have a mean of 8.1 ounces and standard deviation of 0.3, how many of the 12 listed amounts comes within 1.5 std dev of the mean?

Four
Six
Nine
Ten
Eleven

What are the 12 listed amounts?

[karthikpandian19]

sorry abt tht...adding now...

A vending m/c is designed to dispense 8 ounces of coffee per cup. After a test that recorded no of ounces of coffee in each of the 1000 cups dispensed by the vending m/c, the 12 listed amounts, in ounces, were selected for the data. if the 1000 recorded data have a mean of 8.1 ounces and standard deviation of 0.3, how many of the 12 listed amounts comes within 1.5 std dev of the mean?

Four
Six
Nine
Ten
Eleven

What are the 12 listed amounts?

[Anurag@Gurome]

sorry abt tht...adding now...

S.D. = 0.3 implies 1.5 S.D. = 0.3 * 1.5 = 0.45
Mean = 8.1
"Within 1.5 standard deviation of the mean" means mean in the range 8.1 - 0.45 and 8.1 + 0.45, which means in the range 7.65 and 8.55
From the 12 listed amounts only 7.51 is not in the range, which means 11 amounts are within the range.

The correct answer is E.

[karthikpandian19]

I didnt understand:

S.D. = 0.3 implies 1.5 S.D. = 0.3 * 1.5 = 0.45

sorry abt tht...adding now...

S.D. = 0.3 implies 1.5 S.D. = 0.3 * 1.5 = 0.45
Mean = 8.1
"Within 1.5 standard deviation of the mean" means mean in the range 8.1 - 0.45 and 8.1 + 0.45, which means in the range 7.65 and 8.55
From the 12 listed amounts only 7.51 is not in the range, which means 11 amounts are within the range.

The correct answer is E.

[Anurag@Gurome]

I didnt understand:

S.D. = 0.3 implies 1.5 S.D. = 0.3 * 1.5 = 0.45

It's given that standard deviation = 0.3, so 1.5 * standard deviation means 1.5 * 0.3 = 0.45

[karthikpandian19]

Oh...Ok

I assumed / interpreted that the SD to be 1.5......

I didnt understand:

S.D. = 0.3 implies 1.5 S.D. = 0.3 * 1.5 = 0.45

It's given that standard deviation = 0.3, so 1.5 * standard deviation means 1.5 * 0.3 = 0.45