Answer:
z = 1.83<1.96
null hypothesis is accepted
The sample is came from a population mean
Step-by-step explanation:
<u>Step</u> :-1
The sample of 40 measured voltage amounts from a unit have a mean of 123.59 volts and a standard deviation of 0.31 volts
given sample size n =40
mean of the sample ×⁻ = 123.59 volts
standard deviation of sample σ = 0.31 volts
<u>Step2</u>:-
<u>Null hypothesis</u> :-
the sample is from a population with a mean equal to 120 volts.
H₀ : μ =120
<u>Alternative hypothesis:-</u>
H₁ : μ ≠120
<u>level of significance</u>:- α =0.05
<u>Step 3:</u>-
<u>The test statistic</u>
substitute values and simplification
on simplification we get the calculated value
z = 1.83
The tabulated value z =1.96 at 0.05 % level of significance
<u>Conclusion</u>:-
Calculated Z < The tabulated value z =1.96 at 0.05 % level of significance
so the null hypothesis is accepted
The sample is came from a population mean