25% because 21 is a quarter of 84. And 21 times 4= 84, so 21 is 25% of 84.
13t-13t=0
so your left with
6=12
which is a false statement which makes this equation have no solutions
15. [4] insufficient information. only given SA
16. There are 3 right triangles, 3 Pythagorean theorem equations
x²+b²= 16²
12²+a² = x²
a²+4² = b²
combine equations using substitution to get in terms of only x
substitute b² for (a² +x²) in first equation
x²+a²+4²=16²
substitute a² for (x² - 12²)
x²+x²-12²+4² = 16²
solve for x
2x² - 144 + 16 = 256
2x² = 256 + 144 - 16
2x² = 384
x² = 384/2
x² = 192
x = 13.85
rounded to nearest tenth, x = 13.9
Answer:
25.50
Step-by-step explanation:
-5 notebooks $2 each
-4 pencils $1.50 each
-2 packs of markers $3.75 each
5(2)+4(1.50)+2(3.75)
$23.5
23.5 times 8.5/100
1.9975
plus 23.5
25.4975
rounded to 25.50
Given:
250 sheep in a 40-acre pasture.
Number of sheep grazing in each acre.
250/40 = 6.25 or 6 sheep per acre
n = 6
sample proportion: signified by ρ
Sample 1: 4 → 4/6 = 0.67
Sample 2: 1 → 1/6 = 0.17
Sample 3: 9 → 9/6 = 1.50
multiply the sample proportion by 1-ρ
Sample 1: 0.67(1-0.67) = 0.67(0.33) = 0.2211
Sample 2: 0.17(1-0.17) = 0.17(0.83) = 0.1411
Sample 3: 1.50(1-1.5) = 1.5(-0.5) = -0.75
divide the result by n. n = 6
Sample 1: 0.2211/6 = 0.03685
Sample 2: 0.1411/6 = 0.02352
Sample 3: -0.75/6 = -0.125
square root of the quotient to get the standard error.
Sample 1: √0.03685 = 0.1919
Sample 2: √0.02352 = 0.1534
Sample 3: √-0.125 = invalid
z value 95% confidence 1.96.
Sample 1: 1.96 * 0.1919 = 0.3761 or 37.61% margin of error
Sample 2: 1.96 * 0.1534 = 0.3007 or 30.07% margin of error
