6x+5=29
29-5=24
6x=24
24/6=4
x=4
Answer: We are 95% confident that the mean SPF level of sunscreen used by all Cal Poly students is between 29.0813 and 40.0187.
Step-by-step explanation:
Given : Significance level :
Sample size : n= 52 , which is a large sample (n>30), so we use z-test.
By using z-value table,
Critical value:
Sample mean :
Standard deviation :
The confidence interval for population means is given by :-
i.e.
Now, the 95% confidence interval for the ppopulation mean = . (29.0813, 40.0187)
Hence, We are 95% confident that the mean SPF level of sunscreen used by all Cal Poly students is between 29.0813 and 40.0187.
<h3>
Answer: 12pi millimeters</h3>
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Explanation:
The circumference of a circle is the distance around the full circle, aka the perimeter.
The formula for the circumference is
C = pi*d
where d is the diameter. The radius given is 6, so the diameter is 2*6 = 12.
The circumference, is therefore:
C = pi*d
C = pi*12
C = 12pi millimeters
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As a slight alternative, you can use this formula
C = 2*pi*r
with r = 6 as the radius
C = 2*pi*r
C = 2*pi*6
C = 2*6*pi
C = 12pi
We get the same answer as before.