Can someone please help me? I've been trying to figure this out for days. I don't understand how to construct a confidence interval. I know that the red box has a mean value of 15.11 and the blue box's mean is 16.83. The difference of sample means is 1.74. The red standard deviation is 3.868 and the blue one is 2.933. the standard deviation of the sample mean differences is 0.69. How do I use all this to construct the interval with no difference between the population means.

Step-by-step explanation:

Confidence interval is:

CI = x ± CV · SE

where x is the mean, CV is the critical value, and SE is the standard error.

There is no difference between the population means, so x = 0.

The confidence level is 95%, so CV = 1.96.

SE = 0.69.

So the confidence interval is:

CI = 0 ± (1.96) (0.69)

CI = (-1.35, 1.35)

1.74 is outside of the confidence interval, so it is statistically significant.

step-by-step explanation:

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.