Yeast cells are suspended in a liquid medium. A 2 mL sample of the suspension is withdrawn. A total of 56 yeast cells are counted.a. Estimate the concentration of yeast cells per mL of suspension, and find the uncertainty.________________b. What volume of suspension must be withdrawn to reduce the uncertainty to 1 cell per mL?

Solution :

Step 1 of 2:

Given,

A sample of the suspension is withdrawn is 2 ml and

So t=2 ml.

The number of yeast cell counted is 56.

So X=56.

Our goal is :

a). We need to estimate the concentration of yeast cell per ml of suspension and find the

Uncertainty.

b). We need to find what volume of suspension must be withdrawn to reduce the uncertainty

to 1 cell per ml.

a).

Now we have to estimate the concentration of yeast cell per ml of suspension.

Then we have to find the uncertainty.

Then the estimate the concentration of yeast cell per 1 ml is

We know that t=2 and X=56.

Therefore the estimate the concentration of yeast cell per 1 ml is 28.

Then we have to find the uncertainty.

The uncertainty is is

We consider .

Then substitute values.

Therefore the the uncertainty is 3.7416.

Hence .