Table showing with Covid-19 confirmed cases with deaths in USA and Brazil as on July 8,
2020
|
|
|
Confirmed
|
|
Deaths
|
|
USA
|
|
2923432
|
|
129963
|
|
Brazil
|
|
1623284
|
|
65487
|
|
|
|
Source: WHO
Let P1 and P2 be the proportion of deaths to
confirmed cases of Covid-19.
We set Null Hypothesis H0: P1 = P2
Then the Alternative Hypothesis is H1:: P1 # P2
We have, p = (n1p1+n2p2)/(n1+n2)
and S.E. of (p1-p2) = √(pq)(1/n1+1/n2)
Z
= |p1-p2|/S.E. of (p1-p2)
|
USA
|
2923432
|
|
129963
|
||||||||||||||||
|
Brazil
|
1623284
|
|
65487
|
||||||||||||||||
|
4546716
|
|
195450
|
|||||||||||||||||
|
n1=
|
2923432
|
p1=
|
0.044456
|
1/n1=
|
3.42064E-07
|
||||||||||||||
|
n2=
|
1623284
|
p2=
|
0.040342
|
`/n2=
|
6.16035E-07
|
||||||||||||||
|
a1=
|
129963
|
p=
|
0.043
|
q=
|
0.957
|
||||||||||||||
|
a2=
|
65487
|
√pq(1/n1+1/n2)=
|
0.000198533
|
||||||||||||||||
|
1/n1+1/n2
|
9.58099E-07
|
||||||||||||||||||
|
|p1-p2|=
|
0.004113
|
||||||||||||||||||
|
Z=
|
20.72
|
||||||||||||||||||
|z| = 2.58 at 1% level of significance. We reject the Null Hypothesis H0
as obs|z| = 20.72 and conclude that
proportion of deaths due to Covid-19 is significantly higher in USA than in Brazil.