Answer:
sample size require is 1.4
Step-by-step explanation:
Given data:
Selling price $2000
Rating ( range) for purchaing 7
standard deviation is given as[tex]=\frac{ range -1}{6}[/tex]
[tex] = \frac{7-1}{6} = 1[/tex]
[tex]\sigma = 1[/tex]
for 95% confidencwe interval z value is 1.96
margin of error is given as E
[tex]E = Z \times \frac{\sigma}{\sqrt{n}}[/tex]
putting all value to get the margin of error value
[tex]E = 1.96 \times \frac{1}{\sqrt{1.4}}[/tex]
E = 1.65
Sample size is given as [tex]n = [\frac{2\times \sigma}{E}]^2[/tex]
[tex]n = [\frac{1.96 \times 1}{1.65}]^2[/tex]
n = 1.4