Answer:
I think its the last one
Step-by-step explanation:
9.4 because the number after the firs decimal point is higher than 5
Answer:
a
The null hypothesis is 
The alternative hypothesis is 
b
The sample proportion is 
Step-by-step explanation:
From the question we are told that
The sample size is n = 546
The number of people that use a laptop overnight is 
The population proportion is 
Generally
The null hypothesis is 
The alternative hypothesis is 
Gnerally the sample proportion is mathematically represented as

=> 
=> 
Answer:
20
Step-by-step explanation:
f = 2f - 20
f - 2f = - 20
- f = - 20
f = 20