Answer: a. $128.125
Step-by-step explanation:
The standard error of the mean is given by :
, where
= population standard deviation , n= sample size.
Given: 
n= 256
Then, the standard error of the mean:-

Hence, option a. is correct.
I think 3.16 I said I think
Using a confidence interval of proportions, it is found that the correct statement is given by:
D a confidence interval for estimating the cricket's true probability of landing on its feet is more narrow after the final 10 jumps than it was before the final 10 jumps.
<h3>What is a confidence interval of proportions?</h3>
A confidence interval of proportions is given by:

In which:
is the sample proportion.
The margin of error is given by:

The margin of error is inversely proportional to the square root of the sample size, hence, the higher the sample size, the narrower the interval is, hence option D is correct.
More can be learned about a confidence interval of proportions at brainly.com/question/25890103
Answer:
sorry I need to answer this I'll give you the right answer soon I swear