Find a particular solution of the non-homogeneous system of…

Find a particular solution of the non-homogeneous system of differential equations \[ X’ = \left[ \begin{array}{ll} 2 & 3 \\ 1 & 4 \end{array} \right]X   + \left[ \begin{array}{r} 3e^{2t} \\ 0 \end{array} \right]  + \left[ \begin{array}{r} 0 \\ 5 \end{array} \right]  \]

Julie’s research work requires her to interview a sample of…

Julie’s research work requires her to interview a sample of 200 people within 2 months. She needs to gather data about the sample group’s attitude toward certain situations through a questionnaire, but she has limited time to gather the information. Which of the following methods should Julie use to gather the required information?