Question

Part AIvy randomly surveys students in her school to learn about mobile phone password use. Of 25 respondents, 14 use a password. Based on Ivy'sdata, how many of the 275 students in her school would be expected to use a password? Enter your answer in the box.154studentsPart BIf Ivy conducted her survey of 25 students on a volunteer basis, are the results representative of the school? Why or why not?No; The sample size is large, but likely biased.No; The sample size is small and not randomly selected.!!!!15]Yes; The sample size is large and randomly selected.Yes; The results match what Ivy expected.

Answer 1

Part A.

To find the expected value, first, we find the probability of the event: a student that uses a password.

`P_{\text{use}}=(14)/(25)`

Then, we multiply this probability by the number of students 275 to find the expected number

`E=(14)/(25)\cdot275=14\cdot11=154`

The number of students expected to use passwords is 154.

Part B.

It's important to know that a sample has to be good enough in order to represent the population. In this case, a sample of 25 students out of 250 is not enough representation. Also, there's no random sampling process implemented.

Hence, the answer is: No; The sample size is small and not randomly selected.