One of the major problems with mail surveys is nonresponse bias. In an effort to minimize this, a researcher decides to limit the sample to his personal friends from whom he is sure to get replies. This is an example of a:

Solve the word problem. the table shows the low outside temperatures for monday, tuesday, and wednesday. by how many degrees did the low temperature increase from monday to tuesday? this function table shows the outside temperature for a given a. 21.1⁰ b. 8.6⁰ c. 4.9⁰ d. 3.9⁰(the picture is the graph the the question is talking about.)

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

The magnitude, m, of an earthquake is defined to be m=log l/s, where i is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and s is the intensity of a “standard” earthquake, which is barely detectable. what is the magnitude of an earthquake that is 1,000 times more intense than a standard earthquake? use a calculator. round your answer to the nearest tenth.