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