Answer: Mean = 20 and standard deviation = 4
Step-by-step explanation:
Let x represents the success of getting the correct answer.
Here, the total number of trials(n) = 100
The probability of getting the correct answer, p = 1/5
Thus, the mean of the number of correct answer,
[tex]\mu_x= np[/tex]
[tex]\mu_x= 100\times 1/5[/tex]
[tex]\mu_x= 20[/tex]
Now, the standard deviation, [tex]\sigma_x= \sqrt{n\times p\times (1-p)}[/tex]
[tex]\sigma_x= \sqrt{100\times 1/5\times 4/5}[/tex]
[tex]\sigma_x= \sqrt{16}[/tex]
[tex]\sigma_x= 4[/tex]
Thus, First option is correct.
