Answer:
A
Step-by-step explanation:
Using the z-distribution, it is found that she should take a sample of 46 students.
<h3>What is a z-distribution confidence interval?</h3>
The confidence interval is:
The margin of error is:
In which:
is the sample mean.
is the standard deviation for the population.
In this problem, we have a 95% confidence level, hence
, z is the value of Z that has a p-value of 
, so the critical value is z = 1.96.
Scores on the math portion of the SAT are believed to be normally distributed and range from 200 to 800, hence, by the Empirical Rule the standard deviation is found as follows:
The sample size is n when M = 29, hence:
n = 45.67.
Rounding up, a sample of 46 students should be taken.
More can be learned about the z-distribution at brainly.com/question/25890103
#SPJ1
If the number is n then
square of 2 times a number
square of 2n
(2n)²
that was your mistake, because (2n)²=4n², not 2n²
the result is 81
(2n)²=81
square root both sides
remember positive and negative roots
2n=+/-9
divide by 2
n=+/-4.5
n=4.5 or -4.5
Answer:
Karson's average speed on his way home was 28 miles per hour.
Step-by-step explanation:
Since Karson drove from his house to work at an average speed of 35 miles per hour, and the drive took him 20 minutes, if the drive took him 25 minutes and he used the same route in reverse, to determine what was his average speed going home, the following calculation must be performed:
60 = 35
20 = X
20 x 35/60 = X
700/60 = X
11.666 = X
25 = 11,666
60 = X
60 x 11.666 / 25 = X
27.99 = X
Therefore, Karson's average speed on his way home was 28 miles per hour.
