Question

You and your lab partner record the following counts of stomata in sunflower leaves.

Sunflower Plant 1 2 3 4 5 6
Stomata (per examination area) 88 93 90 92 75 78

(a) Calculate the standard deviation of the number of stomata for the sunflower leaves.


(b) Calculate the standard error in the number of stomata for the sunflower leaves.

Answer 1

Answer:

a) $7.07$

b) $2.89$

Explanation:

First of all we are required to calculate the mean of the Stomata (per examination area) which is equal to

$\frac{(88 + 93 + 90 + 92 + 75 + 78)}{6}\\= 86$

Now for standard deviation,  the formula is

$\sqrt{\frac{(X - X')^2}{n-1} }$

Where X is the value of number and X' is the value of mean. n is the number of entry.

a)

Substituting the given values in above equation, we get

$\sqrt{\frac{(88-86)^2 + (93 - 86)^2 + (90-86)^2 + (92 -86)^2 + ( 75 -86)^2 + (78 -86)^2}{(6-1)} } \\= \sqrt{\frac{4 + 49 + 16 + 36 + 81 + 64 }{5} } \\= 7.07$

b) Standard error in the number of stomata for the sunflower leaves.

Standard error = $\frac{7.07}{\sqrt{6} } \\= 2.89$