Answer: 222
Step-by-step explanation:
As considering the given description, we have
Population standard deviation: [tex]\sigma=4[/tex]
Margin of error : E = half of width of confidece interval
=[tex]\dfrac{1}{2}\times1=\dfrac{1}{2}=0.5[/tex]
Critical value for 95% confidence interval : [tex]z_{\alpha/2}=1.96[/tex]
Formula to find the sample size : [tex]n=(\dfrac{z_{\alpha/2}\cdot \sigma}{E})^2[/tex]
i.e. [tex]n=(\dfrac{(1.86)\cdot (4)}{0.5})^2[/tex]
[tex]=(14.88)^2=221.4144\approx222[/tex]
Hence, the required minimum sample size = 222
