Which of the Following Statements Are True?
A) the Price $\mu$

Which of the following statements are true?

A) The price paid for using a high confidence level to construct a confidence interval is that the interval width becomes wider.
B) The only 100% confidence interval for the mean $\mu$
Is $( - \infty , \infty )$
)
C) If we wish to estimate the mean $\mu$
Of a normal population when the value of the standard deviation $\sigma$
Is known, and be within an amount B with $100 ( 1 - \alpha ) \%$
Confidence, the formula for determining the necessary sample size n is $n = \left[ z _ { \alpha / 2 } \cdot \sigma / B \right] ^ { 2 }$
)
D) All of the above statements are true.
E) None of the above statements are true.