Suppose the cars in the Peninsula College parking lot are th…

Suppose the cars in the Peninsula College parking lot are the observational units. A portion of the data collected is shown in the table below. *If the table does not appear, click here to download it.    QUESTION. Pick either (a) or (b): a) Specify another variable that could be measured or categorized for this study. Be sure to phrase it as a variable. OR b) Write a research question that can be addressed with the data provided in the table. (A question that cannot be answered using the data in the table will not receive credit.)

A randomized experiment was done by randomly assigning each…

A randomized experiment was done by randomly assigning each participant either to walk for half an hour three times a week or to sit quietly reading a book for half an hour three times a week.  At the end of a year the change in participants’ blood pressure over the year was measured, and the change was compared for the two groups.   QUESTION: The two treatments in this study were…

You and your friend conduct separate observational studies t…

You and your friend conduct separate observational studies to estimate the proportion of PC students that prefer Hawaiian pizza with pineapple and bacon over other varieties of pizza. Consider the population to be all PC students. Your friend randomly selects 20 students from the school and uses the sample proportion of students who prefer Hawaiian pizza to estimate the population proportion of students who prefer Hawaiian pizza. You also randomly select your own sample of 20 students and find the sample proportion of students who prefer Hawaiian pizza.   QUESTION: Are the populations the same for your friend’s study and for yours?

This is another question about the article in the October 20…

This is another question about the article in the October 2018 issue that referred to a study claiming that two-thirds of all portable internet devices in the United States end up in a landfill when they are replaced.   QUESTION: Is this number (two-thirds) a parameter or a statistic?

A 13.5-m boom (the part between points A and B), of a crane…

A 13.5-m boom (the part between points A and B), of a crane lifting a 3000-kg load is shown below. The center of mass of the boom is at its geometric center, and the weight of the boom is 2400 lb. For the position shown, calculate tension T in the cable and the force at the axle A.  

A solid concrete cylinder (r = 2400 kg/m3) with a diameter o…

A solid concrete cylinder (r = 2400 kg/m3) with a diameter of 80.0 cm and a height of 15.0 cm is spinning on a frictionless pivot with an initial rotational velocity of 2.00 RPM (revolutions per minute). You want to stop the cylinder by pressing against the outer edge with a wooden stick, where the coefficient of static friction between the stick and the concrete is 0.750 and the coefficient of kinetic friction is 0.600. If you want to stop the cylinder in exactly 30.0 seconds, with what force must you press the stick against the edge of the cylinder? Recall the moment of inertia of a solid cylinder is ½ MR2.