Answer:
2,655 students
Step-by-step explanation:
The z-score for a 99% confidence interval is z = 2.576
The standard error for a proportion p is:

For a proportion of p =0.20, in order to ensure a standard error of 0.02, the sample size 'n' must be:

Rounding up to the next whole student, the sample size needed is 2,655 students.
Answer:
The mean is 15.93 ounces and the standard deviation is 0.29 ounces.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
7% of the bottles containing this soft drink there are less than 15.5 ounces
This means that when X = 15.5, Z has a pvalue of 0.07. So when X = 15.5, Z = -1.475.




10% of them there are more than 16.3 ounces.
This means that when X = 16.3, Z has a pvalue of 1-0.1 = 0.9. So when X = 16.3, Z = 1.28.




From above

So




The mean is

The mean is 15.93 ounces and the standard deviation is 0.29 ounces.
The equation looks like this

. In an ellipse, a is always the bigger value, so a^2 = 25. This bigger value also tells us which axis is the major one. Sine the bigger value a is under the y^2 of the equation, the major axis is the y-axis. This is a vertical ellipse. The center is always found within a set of parenthesis that exist with the x^2 and the y^2. Since there are no parenthesis with either, there is no side to side movement, nor is there any up or down movement. So the center doesn't move from the origin (0, 0). The vertex is also along the major axis, and if a^2 is 25, then a = 5, so the vertices go up 5 from the center and down 5 from the center. Vertices are (0, 5) and (0, -5). The foci follow the formula

. c is the distance that the foci are from the center.

and c = 3. The foci also lie on the major axis, so the coordinates for the foci are (0, 3) and (0, -3). There you go!
Well it would be 63$ if we are not including tax because 80-17=63
1 meter = 100 centimeters
2.5 meters = 250 cm
If you use 50 cm, then you have
2 meters or 200 cm left