Answer:
x=4
Step-by-step explanation:
Answer:
The width is 
Step-by-step explanation:
From the question we are told that
The population standard deviation is 
The sample size is 
The sample mean is 
Given that the confidence level is 99% then the level of significance is mathematically represented as

=> 
=> 
Next we obtain the critical value of
from the normal distribution table, the value is

Generally margin of error is mathematically represented as

substituting values



The width of the 99% confidence interval is mathematically evaluated as

substituting values


PH = - log [H+]
pH = - log (0.000316227)
pH = 3.5