Question

please help with no 3,4,5 and 6

Thanks

1. What is standard error? Measure of statistical accuracy of an estimate, equal to the standard deviation of the theorental distribution of a large populanon of such estimates 2. What calculation is used to describe the variation in measurements. 3. In experiment 3.2. You will be measuring out 40ml of volume. How many times will you measure 40 ml? 4. What is the difference for each time you measure out 40ml? In other words, how does the experiment differ in each of the 40ml measurements? 5. On a P1000 micropipettor, what does the display read for 1000 ul? (Draw it) 6. On a P200 micropipettor, what does the display read for 100 ul? (Draw it)

Answer 1

3.

According to the instructions given in the screenshot of Measure and Dispensing,

The number of samples to draw a volume of 40 ml will depend on the volume of the pipette used.

e.g. a 10 ml pipette needs 4 samples for a final volume of 40 ml (each sample of 10 ml)

if micropipettes are used,

a P200 micropipette can draw in a maximum volume of 200 µl which is 0.2 ml

Therefore, if we want to use a P200 micropipette to draw 40 ml, we need to take (40/0.2) number of samples.

40/0.2 =200 samples.

If I want to use a P1000 micropipette, then from the figure we see that this pipette can hold a maximum volume of 1 ml, therefore I would need to take 40 samples to get 40 ml.

4. The answer for 4 can only be determined by actually pipetting out the required volume.

5. The answer to this is given in the figure from the screenshot under micropipettes.

The display for 1000 µl in P1000 is

1(in red)

0

0

The st digit (1) is marked in red.

The display for 100µl in a P200 is

1

0

0

Here the 1^st digit (1) is not marked in red.