Question
I need an answer and an explanation please. :)
Saba believes that the average annual income of high school teachers in small metropolitan areas is different than $55,000. She conducts a survey of 1225 teachers in 89 small metropolitan areas and finds that the average income of these 1225 teachers is $52,000. If she runs a hypothesis testing and finds a z value of 6.1, can she conclude that the average annual income of high school teachers in small metropolitan areas is significantly different than $55,000? Use 2% level of significance.
A. Yes (Reject the null hypothesis).
B. No (Reject the null hypothesis).
C. Yes (Fail to reject the null hypothesis).
D. No (Fail to reject the null hypothesis).
The average life of light bulbs produced by SABA Electric Co. is believed to be normally distributed with the mean service life of 920 hours and a standard deviation of 100 hours. A random sample of 100 bulbs is tested and it has a mean life of 905 hours. Can it be concluded that the mean service life of the bulbs is less than the expectation at 1% level of significance?
A. Yes. The mean service life of the bulbs is less than the expectation.
B. No. The mean service life of the bulbs is not less than the expectation.
C. No. The mean service life of the bulbs is more than the expectation.
D. None of the above.
Do employees perform better at work with music playing? Music was turned on during the working hours of a business with 49 employees and their productivity level averaged 5.2. A national study shows that when music is off employees' productivity level is 4.8 on average, with a population standard deviation of 2.1. What can we conclude at the 1% level of significance?
A. Yes. Employees perform better at work with music playing.
B. No. Employees don’t perform better at work with music playing.
C. Employees productivity drops at work with music playing.
D. None of the above
We are interested in determining whether or not managers of small businesses are in favor of minimum hourly wage increase. A random sample of 60 small business mangers showed that 24 of these managers favored minimum hourly wage increase. At 2% level of significance, can we conclude that less than half of all small business managers support the idea of minimum hourly wage increase?
A. Yes (Reject null hypothesis).
B. No (Reject null hypothesis).
C. Yes (Fail to reject null hypothesis).
D. No (Fail to reject null hypothesis).
A. Yes (Reject the null hypothesis). 

B. No (Reject the null hypothesis). 

C. Yes (Fail to reject the null hypothesis). 

D. No (Fail to reject the null hypothesis). 
