A group of students recorded the volume of water using a measuring cylinder in an experiment. The mean volume of water recorded was 1.8 cm3 and the standard deviation was 0.28 cm3. The teacher realized that there was an error in the reading taken by all the students. All the students recorded a reading of 0.6 cm3 above the correct reading at eye-level. Explain how the correct mean volume of water and standard deviation was affected by the error.

It won't just hand you the answer — it asks where you're stuck.How the checker works

Worked solution

1. Correct the mean by subtracting the common error from every recorded value.

Each recorded reading is $0.6\text{ cm}^3$ above the correct reading.

So the correct mean is
$1.8-0.6=1.2\text{ cm}^3.$

2. State the effect on the standard deviation.

Since every reading is reduced by the same amount, the distances of the readings from their mean are unchanged.

Therefore, the standard deviation is unchanged:
$0.28\text{ cm}^3.$

Answer

The correct mean volume is $1.2\text{ cm}^3$ .

The standard deviation is unchanged, so it remains $0.28\text{ cm}^3$ .

AI analysis — may contain mistakes.

Worked this one out on paper? Snap your steps and Gigle's AI math checker will circle the step where it went wrong.