Respuesta :
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)