Answer:
The variance is 20.59; and the standard deviation is 4.5376.
Explanation:
First of all, there are 71% of tweets with no reaction in the study. Thus, the probability (p) is 0.71. Therefor, sample x follows binomial distribution
Secondly, if we randomly select 100 tweets, the sample size (n) will be 100.
The variance is [tex]n*p*(1 - p) = 100*0.71*(1 - 0.71) = 20.59[/tex]
The standard deviation is the root-square of variance. Then, it is sqrt (20.59) = 4.5376
