Task D – correlation
Daniel Kadaš, Puja Kumari
Introduction to Biostatistics
26.4.2022

During a field survey 10 frogs were captured, measured (body length and body mass) and released.
Following data were obtained:
Frog
mass
length
1
7
56
2
10
71
3
11
80
4
8
53
5
9
61
6
14
91
7
8
64
8
11
79
9
12
85
10
8
62
Is there any correlation between body mass and length in frogs?
What is the proportion of variability shared by the two variables?

H0: There is no correlation between body mass and length in frogs.
frogs<-read.delim("clipboard")
cor.test(frogs$mass, frogs$length)
ggplot(data=frogs, aes(x=mass, y=length))+
  geom_point()+geom_smooth(method="lm", colour=1)+
  labs(x="body mass [g]", y="body length [mm]")
This frog's lungs act like noise cancelling headphones

Pearson's product-moment correlation
data:  frogs$mass and frogs$length
t = 9.5911, df = 8, p-value = 1.158e-05
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
 0.8319788 0.9905697
sample estimates:
      cor
0.9591619
Results and conclusion
There is a correlation…
95% of shared variability…