Please use this formula I provided to solve the questions. Answer in A4 papers. with eligible handwriting . Thanks.

(CLO2:PLO4:C3)(CLO2:PLO7:C3) FORMULA SHEET Sturges Rule: No. of classes : c=1+3.3logn iz range Class width : C Arithmetic mean : n n [X () if n is odd X - L + 2 - F Median : + x() if niseven Mode : Standard deviation : 1- 1 s = n-1 IQR : 2 -2 O, at "+ th term 4 Q, at 3(n + 12 th term 3(mean - median) mean - mode Coefficient of skewness : standard deviation Or standard deviation standard deviation Coefficient of variation : x 100% mean Probability : P(AUB) = P(A) + P(B) mutually exclusive events P(AUB) - P(A) + P(B) - P(AnB) not mutually exclusive events P(AnB) - P(A)P(B) independents events P( A/ B) = P(An B) P(B) conditional probability Page 1 of 7 + 157. The average number of concurrent users for IUKL WIFI at 16 randomly selected times is 150 with a standard deviation of 16. (a) Construct the 90% and 95% confidence interval for the actual number of concurrent users. What can you say about the range of 99% confidence interval? (5 marks) (b) Test to determine if we can infer at the 10% significance level that the actual number of IUKL WIFI concurrent users is more than 145.