Statistics I

Daffodil International University Faculty of Science & Information Technology Department of Software Engineering Midterm Examination, Fall 2026 Course Code: STA 101; Course Title: Statistics I Sections & Teachers: A, B, C, D (MST), E, F, G, H (MAUA), I, J (DSA) Time: 1 Hour 30 Mins Marks: 25 Answer ALL Questions [The figures in the right margin indicate the full marks and corresponding course outcomes. All portions of each question must be answered sequentially.] 1 a) A university is conducting a study to investigate the average amount of time students spend studying each day. A sample of 10 students was selected randomly from the university, and their daily study times (in hours) were recorded as follows: 2, 3, 1, 4, 2, 5, 3, 2, 4, and 3. The researchers want to estimate the average daily study time of all students at the university. Identify the following terms in this scenario: Population, Sample, Parameter, Statistic, Variable, and Data. [3] 1 b) Indicate the correct data type (qualitative or quantitative) and the correct levels of measurements. [2] i. The number of phone calls one receives in a day ii. The rank one holds in Scouts 2 The daily wages (taka) of 30 workers are given below: 204, 108, 101, 129, 119, 149, 210, 103, 104, 146, 127, 123, 108, 149, 136, 187, 102, 191, 148, 163, 172, 118, 104, 132, 131, 142, 183, 105, 195, 144. a) Construct a frequency distribution with cumulative and percentage frequencies. [4] b) Compute the 5th Decile and 60th Percentile and comment on the findings. [2] 3 The daily coding output (in hundreds of lines) of two software development teams over six days is given below: Team Alpha | 60 | 75 | 95 | 100 | 55 | 85 Team Beta | 80 | 125 | 90 | 150 | 82 | 95 a) Investigate the mean and variance of both the teams. [4] b) Using the coefficient of variation (C.V.), determine which team has more consistent coding productivity. [3] 4 a) The number of bugs detected in 12 software testing sessions is given below: 25, 30, 35, 40, 42, 45, 48, 50, 55, 60, 65, 105 Detect if there is any outlier(s) in the above dataset. Also Sketch a Box-Whisker plot. [5] 4 b) Determine the shape characteristics of the distribution of software debugging time using the coefficients of skewness and kurtosis. [Given, μ_2=100, μ_3=800, μ_4=27000] [2]