Answer:
atleast 385
Step-by-step explanation:
Given that an electrical power company is looking to expand into a new market. Before they commit to supplying the new area with electricity, they would like know the mean daily power usage for homes there.
Population std deviation = 
Sample size =
STd error of sample mean = 
Margin of error for 95% would be Critical value ( std error)
Here since population std dev is known we can use Z critical value= 1.96

Sample size should be atleast 385
Answer:
d
Step-by-step explanation:
ive had this exac problem before
Answer:
The total mechanical energy is 0.712 J.
Step-by-step explanation:
A blue 573 g mobile is moving on a metal rail. If on the mobile, the spring exerts a force to the right of modulus 0.85 N and in the indicated position the kinetic energy of the mobile-spring system is 0.47 J and its elastic potential energy is 0.242 J. Determine the mechanical energy of the system mobile-spring in the position shown as indicated in the figure.
The total mechanical energy is given by the sum of the kinetic energy and the potential energy.
Kinetic energy = 0.47 J
Potential energy = 0.242 J
The total mechanical energy is
T = 0.47 + 0.242 = 0.712 J
Solve for the first variable in one of the equations, then substitute the result into the other equation.
3. (1/2, -1,2)
4. (2, -4)
You can get step by step at:
https://www.mathpapa.com/algebra-calculator.html
Answer:
74 and 79
6
Step-by-step explanation: