The formula for calculating the standard deviation of the distribution of sample means given by Report Please briefly explain why you feel this question should be reported . Report Cancel $${\sigma _{\overline {{x_1}} - \overline {{x_2}} }} = \sqrt {\frac{{\sigma _1^2}}{{{x_1}}} + \frac{{\sigma _2^2}}{{{x_2}}}} $$ $${\sigma _{\overline {{x_1}} - \overline {{x_2}} }} = {\left( {\sigma _1^2 + \sigma _2^2} \right)^2}$$ $${\sigma _{\overline {{x_1}} - \overline {{x_2}} }} = \frac{{{{\left( {{x_1}} \right)}^2} + {{\left( {{x_2}} \right)}^2}}}{{{\sigma _1} + {\sigma _2}}}$$ $${\sigma _{\overline {{x_1}} - \overline {{x_2}} }} = {\left( {{\sigma _1} + {\sigma _2}} \right)^2}$$ Show answer $${\sigma _{\overline {{x_1}} - \overline {{x_2}} }} = \sqrt {\frac{{\sigma _1^2}}{{{x_1}}} + \frac{{\sigma _2^2}}{{{x_2}}}} $$
