Answer:
a) Sample size = 1691
b) 95% Confidence Interval = (0.3696, 0.4304)
Explanation:
(a) How large a sample n should they take to estimate p with 2% margin of error and 90% confidence?
The margin of error is given by
Where z is the corresponding z-score for 90% confidence level
z = 1.645 (from z-table)
for p = 0.50 and 2% margin of error, the required sample size would be
(b) The advocacy group took a random sample of 1000 consumers who recently purchased this mobile phone and found that 400 were happy with their purchase. Find a 95% confidence interval for p.
The sample proportion is
p = 400/1000
p = 0.40
z = 1.96 (from z-table)
n = 1000
The confidence interval is given by
Therefore, we are 95% confident that the proportion of consumers who bought the newest generation of mobile phone were happy with their purchase is within the range of (0.3696, 0.4304)
What is Confidence Interval?
The confidence interval represents an interval that we can guarantee that the target variable will be within this interval for a given confidence level.
Answer:
Technician B only
Explanation:
During rotor reconditioning, which is the process also known as machining and sanding, where sanding is the involves the application of between 120 and 150 grit sandpaper while using a non-excessive force that is applied non-directionally for up to 60 seconds on each side such that the surface roughness meets OE standards. The rotors are then cleaned by washing after they are serviced before they can then be installed.
Answer:
Given:
efficiency of the turbine, 
= 65% = 0.65
available gross head, 
= 45 m
head loss, 
= 5 m
Discharge, Q = 
Solution:
The nozzle is 100% (say)
Available power at the inlet of the turbine, 
is given by:
(1)
where
= density of water = 997 
acceleration due to gravity, g = 
Using eqn (1):
Also, efficency, is given by:
Answer:
The costs to run the dryer for one year are $ 9.03.
Explanation:
Given that the clothes dryer in my home has a power rating of 2250 Watts, and to dry one typical load of clothes the dryer will run for approximately 45 minutes, and in Ontario, the cost of electricity is $ 0.11 / kWh, to calculate the costs to run the dryer for one year the following calculation must be performed:
1 watt = 0.001 kilowatt
2250/45 = 50 watts per minute
45 x 365 = 16,425 / 60 = 273.75 hours of consumption
50 x 60 = 300 watt = 0.3 kw / h
0.3 x 273.75 = 82.125
82.125 x 0.11 = 9.03
Therefore, the costs to run the dryer for one year are $ 9.03.
