Step-by-step explanation:
A.
- 2
- 0
- -4
- -6
- 8
- 10
- 4
- 12
- 14
- -2
B.
- 6
- 8
- -20
- -4
- 2
- 12
- 8
- 8
- 14
- 12
Answer: r = 7
Step-by-step explanation:
Subtract 12 from both sides to isolate the r variable. You have -42 = -6r. Divide both sides by -6 to get r by itself and you get r = 7. Verify by substituting 7 as the r value and solving the equation.
The value of the given trigonometry function is 2√15/15
<h3>Half angles</h3>
Half angles are trigonometric identities used to express sine, cosine and tangent of half angles.
For instance the value of cos theta is expressed as shown below;
cosФ = cos(Ф/2+Ф/2)
cosФ = cos²Ф/2-sin²Ф/2
cosФ = cos²Ф/2-(1-cos²Ф/2)
cosФ = 1 - 2cos²Ф/2
Given the following parameters
cosФ = -7/15
Substitute
cosФ = 1 - 2cos²Ф/2
-7/15 = 1 - 2cos²Ф/2
-2cos²Ф/2 = -7/15 - 1
-2cos²Ф/2 = -8/15
cos²Ф/2 = 4/15
cosФ/2 = 2/√15
Rationalize
2/√15 * √15/√15
2√15/15
Hence the value of the given trigonometry function is 2√15/15
Learn more on trigonometry function here: brainly.com/question/2254074
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Answer:

Step-by-step explanation:
Given that to save money, a local charity organization wants to target its mailing requests for donations to individuals who are most supportive of its cause.
Men women
Sample size 5 5
Mean rate 6.2 5.3
Mean diffference = 
Std error for difference = 0.25 (given)
Since we have two groups and also sample sizes are very small we can use t significant value for finding out confidence interval
df = 5+5-2 =8
t critical value for 80% two tailed = 1.397
Conf interval 80%
=