Dr. x was conducting an experiment to determine how often americans eat spinach. two weeks into the experiment, there was a massive outbreak of e. coli poisoning with spinach as the source. dr. x noticed a steep decline in spinach consuming habits for months after the outbreak. this is an example of a:

Hello there!

This fact is an example of history effect.

Explanation:

History effects refer to events or circumstances generated in the surroundings that influence or change an experiment, affecting its result within the internal validity method of an investigation. These effects can occur at the beginning, in the middle, or at the end of the experiment.

This case shares an experiment of the eating habits of American people towards spinach. After two weeks, the experiment causes an outbreak of the E. Coli bacteria found in the spinach causing the experiment's main source to be the reason for its end as well.

this is false

richard nixon was the 37th president of the united state and didn't serve as a vice president for any president before him