Experiment 3: speed of transverse waves

the objective for this experiment is to find a relationship between lambda and f in a long spring.
To do so we create a wave in fundamental form from the same spring but each time we change the length.
So each time λ = 2L where L is the distance between the two nodes.

Here is the data collected:

λ , m	T, s	1/T = ƒ, Hz	λ*ƒ, m/s
2.85 ± 0.05	0.423  ± 0.005	2.367 ± 0.005	6.75 ± 0.05
4.90 ± 0.05	0.754 ± 0.005	1.326± 0.005	6.50 ± 0.05
5.52 ± 0.05	0.871 ± 0.005	1.149± 0.005	6.34 ± 0.05
6.62 ± 0.05	1.027 ± 0.005	0.974± 0.005	6.45 ± 0.05

the average of the last column is 6.51 ± 0.17 and since the units are m/s we can assume that it is the value for speed. (λ*ƒ, m *1/s so m/s)
also to back up the theory the graph of λ vs T should look linear. The graph is as follow:

y = 6.4537x


the fitted line is linear and passes through zero and the slop is 6.4537 m/s which is very close to the average of λ*ƒ values. 
As for uncertainty the error in the experiment comes from the non homogeneous shape of the spring and also us not being able to create a perfect fundamental loop since we were creating it with hand.  Also another problem was the exact measuring of time for ten oscillation.