Problem Solving. Solve the following problems. Show all pertinent solutions. No immediate rounding. Round off final answers to three decimal places.

3. Twenty five righthanded students were asked to turn a knob (using their right hands) that moved an indicator by screw action. There were two identical instruments, one with a righthand thread (the knob turns clockwise) and the other with a lefthand thread (the knob turns counterclockwise). The data presented below gives the times (in seconds} each subject took to move the indicator a fixed distance: At 1% level of significance, can we conclude that these right-handed students found it easier to use the knobs with a right-hand thread