Question

HELP PLEASE !!!

Answer 1

@Bigbosssaint21

Answer 2

@AceSpeedFighter Thanks :D

Answer 3

Standard error of the mean = Standard deviation/sqrt n
= 11.5/sqrt 70
= 1.3745

Margin of error = Confidence coefficient*Standard error of mean
= 1.96*11.5/sqrt 70
= 2.694

[Confidence coefficient is the critical value of z for 95% confidence level = 1.96
If the level of confidence is NOT indicated 95% level can be considered]