Answer:
a
The upper bound of the 99% prediction level is
b
The 95% confidence interval is
Step-by-step explanation:
Considering first question
From the question we are told that
The sample size is n = 30
The sample mean is
The standard deviation is
Generally the degree of freedom is mathematically represented as
=>
=>
From the question we are told the confidence level is 99% , hence the level of significance is
=>
Generally from the t distribution table the critical value of at a degree of freedom of is
Generally the 99% prediction level is mathematically represented as
Generally the upper bound of the 99% prediction level is mathematically represented as
=>
=>
Considering second question
Generally the sample is mathematically represented as
=>
=>
Generally the standard deviation is mathematically represented as
=>
=>
Generally the degree of freedom is mathematically represented as
=>
=>
From the question we are told the confidence level is 95% , hence the level of significance is
=>
Generally from the t distribution table the critical value of at a degree of freedom of is
Generally the margin of error is mathematically represented as
=>
=>
Generally 95% confidence interval is mathematically represented as
=>
=>