Answer:
The population mean is 5 volts
Step-by-step explanation:
Output voltage is assumed to be normally distributed, with standard deviation 0.25 Volts
s=0.25
n = 8

Sample mean = 
Since n < 30 and population standard deviation is unknown
So, we will use t test
Formula : 

t=-1.69
Refer the t table for p value
Degree of freedom = n-1 = 8-1 = 7
So,
P value >α
So, We are failed to reject null hypothesis
Hence The population mean is 5 volts
Jump at 5 means that your paying attention
C.
Because deceased means minus, so you eliminate A. Product means multiplication so 3n-7
1 nm = 0.000001 mm
105 * 13.6 * 0.000001 = 0.1428 mm
Answer:
-20
Step-by-step explanation:
-20 divided by -4 is 5.