Dang...H0: μ = 115
HA: μ ≠ 115
Sample mean = 120
Standard deviation = 25
Standard error of mean = σ / √ n
Standard error of mean = 25 / √ 100
SE = 25/10
Standard error of mean 2.5
z = (xbar- μ ) / SE
z = (120-115) / 2.5
z = 2
p-value = 2 P( z > 2) = 2(0.0228) = 0.0456
the data are statistically significant at level = .05, but not at level = .01.
2)
H0: μ = 115
HA: μ ≠ 115
Sample mean = 119
Standard deviation = 25
Standard error of mean = σ / √ n
Standard error of mean = 25 / √ 100
SE = 25/10
Standard error of mean 2.5
z = (xbar- μ ) / SE
z = (119-115) / 2.5
z = 1.6
p-value = 2P( z > 1.6) = 2(0.0548) =0.1096
3)
a statement about the population the researcher suspects is true, and is trying to find evidence for.
4)
Sample mean = 80
Standard deviation = 20
Standard error of mean = σ / √ n
Standard error of mean = 20 / √ 100
SE = 20/10
The Standard error of mean 2
Confidence interval 80-(2)(1.645)
and 80+(2)(1.645)
(76.7, 83.3)
using the LCD method.... well, there are a couple of ways, but let's simply add them up.
well, the denominators are 5x and 2x... so the only LCD will just be 10x, since it's divisible by both, so let's use that one.
Do both as equation it will make it easier for her
So the formula for the area of a trapezium is
area = (a + b)/2 * h
*a is the short side
* b is the long side
*h is the height
so let's plug in the values we already know: area, long base, short base. Here's how the formula looks now...
6550 = (150 + 85)/2 * h
*so, we need to find 'h'
use algebra to find it.
6550 = (235/2) * h
6550 = 117.5 * h
6550/117.5 = h
h = 55.74 (approx)
