Rajesh calculated 95% confidence level. What does he mean by that?

(A) He can be 95% confident that his sample will include the population parameter.

(B) He can be 95% confused that his sample will include the population parameter.

(C) He can be 5% confident that his sample will not include the population parameter.

(D) He can be 5% confident that his sample will include the population parameter.

Choose the correct answer from the options given below:

When Rajesh says he has a 95% confidence level, this means he is 95% confident that the calculated confidence interval (the range from the sample) captures the true population parameter.

Examining option (A): "He can be 95% confident that his sample will include the population parameter."

This statement is correct. A 95% confidence level means there is a 95% probability that the confidence interval calculated from the sample contains the true population parameter.

Examining option (B): "He can be 95% confused that his sample will include the population parameter."

This statement is incorrect. The term "confused" has no mathematical meaning in statistics. The correct term is "confident."

Examining option (C): "He can be 5% confident that his sample will not include the population parameter."

This statement is correct. If there is 95% confidence that the interval will include the parameter, then there is $(100\% - 95\%) = 5\%$ confidence that it will not include it. This represents the complement of statement (A).

Examining option (D): "He can be 5% confident that his sample will include the population parameter."

This statement is incorrect. This contradicts the 95% confidence level stated. The confidence that the interval includes the parameter is 95%, not 5%.

Statements (A) and (C) are both correct, as they represent complementary probabilities:

$95\% + 5\% = 100\%$

Therefore, the answer is: Options (A) and (C)