Penn State extension is interested in comparing the body length southern grass cicadas and citrus cicadas. The extension collected a random sample of 20 southern grass cicadas and found that they have a mean body length of 16.22 millimeters and a standard deviation of 1.34 millimeters. A separate random sample of 20 citrus cicadas resulted in a mean body length of 13.41 millimeters and a standard deviation of .73 millimeters. What is the standard error of the difference parentheses southern grass minus citrus) between the sample means

Respuesta :

Answer:

The standard error between the sample mean is approximately 0.3412

Step-by-step explanation:

The equation for the standard error of a difference in sample mean of equal sample sizes is given as follows;

[tex]SE(\overline x_1 - \overline x_2)={\sqrt{\dfrac{s_{1}^{2} }{n_{1}}+\dfrac{s _{2}^{2}}{n_{2}}}}[/tex]

The given parameters are;

The number of sample of southern grass cicadas, n₁ = 20

The mean body length of the southern grass cicadas, [tex]\overline x _1[/tex] = 16.22 mm

The standard deviation, s₁ = 1.34 mm

The number of sample of citrus cicadas, n₂ = 20

The mean body length of the citrus cicadas, [tex]\overline x _2[/tex] = 13.41 mm

The standard deviation, s₂ = 0.73 mm

[tex]SE(16.22 - 13.41)={\sqrt{\dfrac{1.34^{2} }{20}+\dfrac{0.73^{2}}{20}}} \approx 0.3412[/tex]

The standard error between the sample mean, SE ≈ 0.3412