Answer:
Mean = 24
Variance = 107.78
Standard deviation = 10.38
Hope this helps! :)
Answer:
B. A teacher compares the pre-test and post-test scores of students
Step-by-step explanation:
the answer is true, because it is a good example to compare the tests between students, we know that a matching pair design is a random model and is used when the experiment allows grouping subjects in pairs based on a variable and each pair will receive randomly a different handling, the answer A is not true because in the example all students are uniformly averaged and the variable is not correlated with subgroups, option c is incorrect because the variable was not randomized and generates classification bias and the option d is incorrect because the teacher compares a small sample as her class with a score of a total sample, but does not intervene on her students when selecting the corresponding group
Let cos x = a, then
2a^2 + a - 1 = 0,
solving the quadratic equation, we have:
a = 0.5 or -1.
i.e. cos x = 0.5 or cos x = -1
for cos x = 0.5,
x = pi/3, 2pi - pi/3 = pi/3, 5pi/3
for cos x = -1,
x = pi
therefore, x = pi, pi/3, 5pi/3
Answer: B
4 because triangle based pyramids have four faces
Answer:
The answer would be B, or the second option.
Step-by-step explanation:
To find the volume, you must multiply the length, width, and height of the object. (Length x Width x Height)
<em>l × w × h</em>
Replace each of the following variables with the length of each side. In this case, they are all 3, but remember that it doesn't matter in which order you put them in.
3 × 3 × 3.
Now multiply!
3 × 3 × 3 = 27 cubic feet.
Meaning, the final answer would be B.
