Observation Formulate a Hypothesis Observation Formulate a Hypothesis

Observation Formulate a Hypothesis

Observation Formulate a Hypothesis -a testable statement Model Test the Hypothesis

Scientific Experiment Hypothesis: Vitamins will cause plants to grow faster. Control group serves as a means of comparison. Experimental group Vitamins added

24 H e i g h t 22 Control group Experimental group 20 18 16 14 12 i n c h e s 10 8 6 4 2 1 2 3 4 5 months 6 7 8 9 10 11 12

Scientific Experiment Hypothesis: Vitamins will cause plants to grow faster. Control group serves as a means of comparison. Experimental group Vitamins added

A direct proportion is a relationship where dividing one quantity by another gives you a constant. y x =k Example: 2 1 4 = 2 = 6 3 8 = 4 10 = = 5 12 6

12 10 y a x i s 8 6 4 2 1 2 3 x axis 4 5 6 x y 1 2 2 4 3 6 4 8 5 10 6 12

An inverse proportion is a relationship where multiplying one quantity by another gives you a constant. xy = k Example: or 1 x 24 = k 2 x 12 = k 3 x 8 = k 4 x 6 = k 6 x 4 = k x= k y

24 22 x y 20 1 24 18 2 12 y 16 3 8 14 4 6 6 4 8 3 12 2 a x 12 i 10 s 8 6 4 2 1 2 3 4 5 x axis 6 7 8 9 10 11 12

Number of Workers Dollars per day 1 200 2 400 3 600 4 800 6 1200 8 1600 12 2400

12 workers, $2400 2000 8 workers, $1600 D 1600 o l l a 1200 r s 800 400 6 workers, $1200 4 workers, $800 This relationship and graph show an direct proportion between # of workers and cost 2 workers, $400 1 worker, $200 2 4 6 Number of workers 8 10 12

$200 = $400 = $800 = $1200 = $1600 = $2400 _ worker 2 workers 4 workers 6 workers 8 workers 12 workers $ W =k

Number of x Workers Amount of Time = k 1 x 480 = k 2 x 240 = k 3 x 160 = k 4 x 120 = k 6 x 80 = k 8 x 60 = k 12 x 40 = k wxt=k

12 40 days, 12 workers 11 Workers and Timegraph This relationship 1 480 show an inverse proportion between # of workers 2 240 and time 10 W o r k e r s 9 60 days, 8 workers 8 7 80 days, 6 workers 6 5 4 120 6 80 8 60 12 40 120 days, 4 workers 4 3 160 days, 3 workers 2 240 days, 2 workers 480 days, 1 worker 1 40 80 120 160 200 240 280 320 360 400 440 480 Time (days)