Given:
Confidence level = 90%
mean = 71 beats per minute
standard deviation = 6 beats per minute
margin of error = z * δ / √n
where : δ - population of the standard deviation, n is the sample size ; z is the appropriate z value.
90% confidence level = 1.645 in z-value
margin of error = 1.645 * (6/√80) = 1.645 * (6/8.94) = 1.645 * 0.671 = 1.104
<span><u><em>The correct answer is: </em></u>
B) rotation.
<u><em>Explanation: </em></u>
<span>Reflecting a figure across two intersecting lines changes the orientation of the figure, which is what a rotation does.
The center of this rotation will be at the intersection of the two lines of reflection.</span></span>
0.666667 as a fraction is 2/3
Answer:
405
Step-by-step explanation:
To find sample size, use the following equation, where n = sample size, za/2 = the critical value, p = probability of success, q = probability of failure, and E = margin of error.

The values that are given are p = 0.84 and E = 0.03.
You can solve for the critical value which is equal to the z-score of (1 - confidence level)/2. Use the calculator function of invNorm to find the z-score. The value will given with a negative sign, but you can ignore that.
(1 - 0.9) = 0.1/2 = 0.05
invNorm(0.05, 0, 1) = 1.645
You can also solve for q which is 1 - p. For this problem q = 1 - 0.84 = 0.16
Plug the values into the equation and solve for n.

Round up to the next number, giving you 405.
Attached you will see the solution using the trig plane and general solutions.