Question

A florist wanted to investigate whether a new powder added to the water of cut flowers helps to keep the flowers fresh longer than just water alone. For a shipment of roses that was delivered to the store, the florist flipped a coin before placing each rose in its own individual container with water. If the coin landed heads up, the rose was placed in water with the new powder; otherwise, the rose was placed in water alone. Which of the following is the best description of the method used by the florist?

A. A census, because all roses are assigned to a container
B. An experiment with a completely randomized design
C. An experiment with a blocked design, with blocking by type of water
D. An experiment with a matched-pairs design
E. An observational study

Answer 1

An experiment with a completely randomized design

Step-by-step explanation:

Answer 2

B. An experiment with a completely randomized design

Step-by-step explanation:

A requirement for experiments is the random assignation of participants to the groups, in order to avoid characteristics or variations within the individual participants to affect the experiment. This is because what we want to determine is precisely our independent variable (the one we are manipulating, in this case the use of the powder) affects significantly our dependent variable (the one we are measuring, in this case the time of freshness) in our subjects (in this case the flowers). Since we only have two groups: a control and an experimental group, we have a 50% percent chance of either, making a coin a perfect way to randomly assign.