Answer: 1.467
Step-by-step explanation:
Formula of Margin of Error for (n<30):-

Given : Sample size : n= 22
Level of confidence = 0.90
Significance level : 
By using the t-distribution table ,
Critical value : 
Standard deviation: 
Then, we have

Hence, the margin of error for the confidence interval for the population mean with a 90% confidence level =1.467
31
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100 that's is what I got in the lowest form x
Since 20 is a factor of 40, the least common denominator of 3/20 and 9/40 is 40.
The answer would be 11x-12