In february, alec had 1,525 visitors to his website. in march, he had 1,349 visitors to his website. what is the percentage decrease of the number of visitors to alec's website from february to march? if necessary, round to the nearest tenth of a percent.

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected

Arectangular courtyard is 12 feet long and 8 feet wide. a tile is 2 feet long and 2 feet wide. how many tiles are needed to cover the courtyard?