Answer:
Step-by-step explanation:
Hello!
The Confidence intervals for the population mean to follow the structure "point estimation"±" margin of error"
You as the store owner took a sample to determine the average amount of money a typical customer spends on your shop.
n= 26 customers.
X[bar]= $77.506
S= $11.0714
Assuming the variable X: the amount of money spent by a typical customer has a normal distribution and that there is no information about the population standard deviation, the best statistic to use for this estimation is a Students-t:
[X[bar] ± [tex]t_{n-1;1-\alpha /2}[/tex] * [tex]\frac{S}{\sqrt{n} }[/tex]]
[tex]t_{n-1; 1-\alpha /2}= t_{25; 0.995}= 2.787[/tex]
The margin of error of the interval is:
d= [tex]t_{n-1;1-\alpha /2}[/tex] * [tex]\frac{S}{\sqrt{n} }[/tex]
[tex]d= 2.787 * \frac{11.0714}{\sqrt{26} }[/tex]
d= 6.051
I hope it helps!
