Question

the red blood cell counts (in 10^5 cells per microliter) of a healthy adult measured on 5 days are as follows. 55, 51, 50, 54, 55 send data to calculator find the standard deviation of this sample of counts. round your answer to two decimal places.

Explanation:

Step1: Calculate the mean

The mean $\bar{x}=\frac{55 + 51+50+54+55}{5}=\frac{265}{5}=53$.

Step2: Calculate the squared - differences

$(55 - 53)^2=4$, $(51 - 53)^2 = 4$, $(50 - 53)^2=9$, $(54 - 53)^2 = 1$, $(55 - 53)^2=4$.

Step3: Calculate the variance

The variance $s^{2}=\frac{4 + 4+9+1+4}{5 - 1}=\frac{22}{4}=5.5$.

Step4: Calculate the standard deviation

The standard deviation $s=\sqrt{5.5}\approx2.35$.

Answer:

$2.35$