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.
A 80 square meter I’m not quite sure
Answer:
3.141592653589793238
Step-by-step explanation:
Succinctly, pi—which is written as the Greek letter for p, or π—is the ratio of the circumference of any circle to the diameter of that circle. If you divide the circumference of the circle by the diameter, you will get approximately 3.14—no matter what size circle you drew! A larger circle will have a larger circumference and a larger radius, but the ratio will always be the same. If you could measure and divide perfectly, you would get 3.141592653589793238..., or pi.
Answer:
Surface area of the refrigerator is 864 in².
Step-by-step explanation:
Formula to calculate the surface area of a cube is,
Surface area = 6s²
Here, s = length of a side of the cube
If side length 's' = 12 inches
By substituting this value in the formula,
Surface area = 6(12)²
= 6 × 144
= 864 inch²
Therefore, surface area of the refrigerator is 864 in².
Answer:
Step-by-step explanation:
If the radius of a circle is doubled, the area of the circle will be quadrupled and the circumference will also be doubled. This makes sense because the area of a circle is directly proportional to the square of the radius of the circle (if the radius of a circle is increased x times, its area will be increased to x^2 times the original area), whereas the circumference is proportional to the size of the radius (if the radius of a circle is increased x times, its circumference will increase x times).
