Answer: 1.24
Step-by-step explanation:
Let p be the population proportion of the total market share for one of its products.
As per given , we have
p=0.30
Sample size : n= 144
Sample proportion : [tex]\hat{p}=\dfrac{50}{144}=0.347222222222\approx0.3472[/tex]
Formula for z-value :-
[tex]z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}[/tex]
i.e. [tex]z=\dfrac{0.3472-0.30}{\sqrt{\dfrac{0.30(1-0.30)}{144}}}[/tex]
Simplify ,
. [tex]z=1.2359861303\approx1.24[/tex]
Hence, the observed z value would be 1.24 .