Answer: 1.303639
Step-by-step explanation:
The t-score for a level of confidence
is given by :_
, where df is the degree of freedom and
is the significance level.
Given : Level of significance : 
Then , significance level : 
Sample size : 
Then , the degree of freedom for t-distribution: 
Using the normal t-distribution table, we have

Thus, the t-score should be used to find the 80% confidence interval for the population mean =1.303639
Answer:
Which one have same variable gather or decrease up
Step-by-step explanation:
2x^2-4.6x^2=1.4x^2
-7x+7x=0
1.4x^2+2<0
x<0
Answer:

Step-by-step explanation:
Given:
The equation of the known line is:

A point on the unknown line is (-4, 4)
Now, since the two lines are parallel, their slopes must be equal.
Now, slope of the known line is the coefficient of 'x' which is
.
Therefore, the slope of the unknown line is also 
Now, for a line with slope 'm' and a point on it
is given as:

Here,
. Therefore,

Hence, the equation of the unknown line is
.
Answer:
x = 136/35; y = -⁹/₁₀
Step-by-step explanation:
(1) 7x + 8y = 20
(2) 7x – 2y = 29 Subtract (2) from (1)
10y = -9 Divide each side by 10
(3) y = -⁹/₁₀ Substitute (3) into (1)
7x - 2(-⁹/₁₀) = 29
7x + 18/10 = 29 Subtract 18/10 from each side
7x = 29 - 18/10
7x = (290 - 18)/10
7x = 272/10 Divide each side by 7
x = 272/70
x = 136/35
x = 136/35; y = -⁹/₁₀
Check:
(1) 7(136/35) + 8(-⁹/₁₀) = 20
136/5 - 72/10 = 20
136/5 - 36/5 = 20
100/5 = 20
20 = 20
(2) 7(136/35) – 2(-⁹/₁₀) = 29
136/5 + 18/10 = 29
136/5 + ⁹/₅ = 29
145/5 = 29
29 = 29
Answer:
I'm not sure about "11" but 12. is "by the definition of right angles", and 16. is "by the SAS(side angle side) congruency theorem"