Question

marcella has read an article on the internet that says plants grow better in acidic soil. she decides to test this statement by adding 15 milliliters of vinegar to the 0.5 l water container she uses to water one row of her marigolds. on the other row, she waters her marigolds with regular water from a 0.5 l container. she measures her marigold’s height each week for six weeks. 1. the independent variable: a) the height of the marigolds b) the amount of water used on the plants c) the presence of vinegar in the water d) the length of time the marigolds are measured

Explanation:

An independent variable is what is changed or controlled in an experiment. Here, Marcella changes whether vinegar is added to the water used for watering marigolds. The height of marigolds is the dependent variable (changes based on other factors), amount of water is kept constant (0.5 L), and length - of - time of measurement is a fixed parameter. The presence of vinegar is what she manipulates.

Answer:

c) the presence of vinegar in the water