Answer:
y+72=340
Step-by-step explanation:
Answer: 17.89
Step-by-step explanation:
In binomial distribution, the standard deviation is given by :-

As per given , we have
The number of vouchers in the sample with errors is denoted by x.
p= 0.20 , n = 2000
Then , 

Hence, the standard deviation of x is 17.89.
Answer:
The answer is "At the 0,10 level, there should be enough proof that the percentage is below 49%"
Step-by-step explanation:
Null and alternative hypothesis:
Significance level:
It is decided that the null hypothesis at the defined meaning level is rejected.