Scientific Skills #5

A student hypothesized that robins prefer large birdhouses to small ones. He build four birdhouses of different sizes to test his hypothesis. What was the independent variable in the students study?

• The size of the birdhouse
• The number of birds in the house
• The location of the birdhouse
• The season of the year

Sabrina wants to test which brand of popcorn pops the most kernels.  She picked a store brand, Orville Redenbacher, and PopSecret.  All three bags started with the same number of kernels.  She popped each for 3 minutes in the same microwave, and then counted the number of kernels left over.  What is her independent variable?

• Number of kernels left over
• Brand of popcorn
• number of kernels before popping
• length of time cooking

Kira wants to test which type of soda creates the biggest foam explosion when adding a Mentos candy.  She chose Sprite, Coke, and Mountain Dew.  One at a time, she added a single Mentos candy and measured the height of the foam eruption.  Mountain Dew created a foam eruption of 7 inches.  Coke and Sprite tied at 5 inches.  What is her dependent variable?

• Brand of soda
• Number of mentos candies used
• Height of foam eruption
• Temperature of soda

The __________ variable is located on the y-axis.

• Independent
• Dependent
• Control
• Constant

When scientists collect data that is measurable with numbers, we call it...

• qualitative data
• quantitative data
• hypothetical data
• graphing data

A student wants to test the effects of type of exercise on heart rate.  What is the dependent variable?

• heart rate
• type of exercise
• amount of exercise
• time of day exercise occurs

What is the volume of the fish?

• 18.0 mL
• 6.0 mL
• 38.0 mL

How many students have more than 1,000 songs on their MP3 player?

• 5
• 16
• 10
• 4

What is the difference between the number of frogs in the pond when the rainfall was 5cm and when the rainfall was 20cm?

• 20

• 40

• 50

• 60

Vicky completed an investigation into the amount of bacteria on a plate. She calculated the average (mean) amount to be 68.25252525. What is this value to 3s.f.?

• 68.3

• 68.25

• 68

• 68.2