The average monthly energy usage in kilowatt-hours for households in a suburban area is 1,200 kWh, with a standard deviation of 150 kWh. A random sample of 64 households is selected. Let $\overline{X}$ represent the mean energy usage of the sample. Find the energy usage that separates the bottom 10% of the sample mean energy usages.
NORM.INV(0.10, 1200, 150)
1-NORM.DIST(1200, 150, 64, TRUE)
NORM.INV(0.10, 1200, 150/SQRT(64))
1-NORM.INV(0.10, 1200, 150/SQRT(64))
NORM.INV(1-0.10, 1200, 150/SQRT(64))
NORM.S.INV(0.10)