Which type of sampling method is being used in the following scenario: A Starbucks manager wants to do a study on the customer's level of satisfaction with
their service. He selects the first 50 customers that use the drive thru to rate their
satisfaction of their service on a scale of 1 to 10.

Voluntary Response Sample
Systematic Sample
Cluster Sample
Convenience Sample
Stratified Sample
Simple Random Sample

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.

52 cm radius = diameter = area = circumference = circumfer