(1 point) juan makes a measurement in a chemistry laboratory and records the result in his lab report. the standard deviation of students' lab measurements is σ = 13 milligrams. juan repeats the measurement 6 times and records the mean x⎯⎯⎯ of his 6 measurements. (a) what is the standard deviation of juan's mean result? (that is, if juan kept on making 6 measurements and averaging them, what would be the standard deviation of all his x⎯⎯⎯′s? ) (b) how many times must juan repeat the measurement to reduce the standard deviation of x⎯⎯⎯ to 3.25?

Si la base de un triángulo isósceles mide 70 m y el ángulo opuesto a ésta mide 58°; entonces ¿cuánto mide la altura de dicho triángulo? a) 21.87 m. b) 40.01 m. c) 43.74 m. d) 63.14 m.

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?

Graph the line y=4/3 x+1 . use the line tool and select two points on the line.