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 + 15SECTION B Styles There are TWO (2) questions in this section. Answer ANY ONE (1) question. No 1. It has been reported that on average, college students spent 3 hours per day watching YouTube. Ne A sample of 12 college students have been taken and time in hour (x) they spent watching YouTube have been recorded as follow: Pick 4.2 a 1.8 3.1 4.4 1.3 H 2.7 3.9 4.3 0.8 3.4 6.1 H (a) Given that that E x2 =170.03, use the formula to determine the point estimators of He population mean and standard deviation. (4 marks) H He (b) Find a 90% and 95% confidence interval for population mean. What can you summarize from the findings when we increase the confidence level from 90% to 95%? (6 marks) (c) Test at 0.1 significance level, is it on average, college students spent more than 3 hours per HE day watching YouTube? (5 marks). (d) If the significance level is reduced to 5%, can you conclude that college students spent No hours per day watching You Tube? more than Show (5 marks) Page: 9/12 Section: 1/1 SetValue: 17.8cm Row: 28 Column: 8 Words: 1339 Spell Check Num: 92. The following table gives information on the ages (in years) and the number of breakdown Styles a during the past month for a sample of seven machines of a large firm. Age (in years) No. of Breakdowns 14 10 New 8 6 11 12 Pick fo 3 H 4 6 5 He 2 2 He 18 15 Hea (a) Identify the dependent variable (v), and independent variable (x) and explain the selection of dependent and independent variables. (2 He marks) (b) Find the regression equation for this data. (6 Hea marks) (c) Interpret the values of Bo and B, in this study. (2 Hea mark) (d) Estimate the number of breakdowns for a machine which has been used for 8 years. Norm Compare your answer with the actual number of breakdowns for a machine which has been Show: used for 8 years to determine the residual of the number of breakdowns monthly sales for a has used machine which for Sho been years (3 marks) Spell Check Page Num: 10 Page: 10/11 Section: 1/1 SetValue: 14.9cm Row: 24 Column: 7 Words: 1339 O V