30 35 23 22 28 39 21 Population 2 45 49 15 34 20 49 36 Use this data to find the 90% confidence interval for the true difference between the population means. Assume that both populations are normally distributed. Step 3 of 4 : Calculate the margin of error to be used in constructing the confidence interval. Round your answer to six decimal places.

(−14.850850 ; 0.565135)

Step-by-step explanation:

Confidence interval :

Xd ± Tcritical * Sd/√n

Population 1 :30 35 23 22 28 39 21

Population 2 : 45 49 15 34 20 49 36

d = -15,-14,8,-12,8,-10,-15

The mean of d, Xd = Σx / n = - 7.14285714

The standard deviation of the difference, Sd = 10.4948967 (using calculator)

Sample size, n = 7

Tcritical at 90%, df = 7 - 1 = 6

Tcritical = 1.943176

Confidence interval :

- 7.14285714 ± 1.943176 * 10.4948967/√7

Confidence interval :

- 7.14285714 ± 7.7079925

(−14.850850 ; 0.565135)

omg what happend to your question? if you could edit this question i can

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.