The price of a shirt is usually £45. During a sale the prices in the shop are reduced by 2 5 . How much is the shirt in the sale
1 answer:
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Answer: 1692
Step-by-step explanation:
Formula to find the sample size :
Given : Confidence level :
⇒ significance level =
z-value for 90% confidence interval (using z-table)=
Prior estimate of the population proportion (p) of customers who keep up with regular vehicle maintenance is unknown.
Let we take p= 0.5
Margin of error : E= 2%=0.02
Now, the required sample size will be :
Simplify , we get
Hence, the required sample size = 1692