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.
Answer:
A) 0 (no solutions)
Step-by-step explanation:
Solve the equation:
3x - 10(x+2) = 13 - 7x
3x - 10x -20 = 13 - 7x
-7x - 20 = 13 - 7x
-20 = 13
Since both sides are clearly not equal to each other, no solution can satisfy both sides to be equal to each other. So A is correct.
Hey!
The area of the circle would be 28.26 feet squared
Lets break it down:
The formula for the area is pi×radius×radius
We have the diameter, so to find the radius, we need to divide the diameter by 2. 6÷2=3
Now that we have the radius, wr can plug in our numbers: 3.14×3×3= the area, or 28.26 feet sq.
Hope this helps!
The answer is B. Because there are 8 ribbons in all. 1 ribbon is black. so the equation would be 1/8. Assuming you don't draw the black ribbon on the first try, then you would try again. The second time you draw a ribbon you don't put the ribbon you drew back in. That means there are only 7 ribbons the second time. The 1 black ribbon is still in the bag than the equation would be 1/7. Then you add the two together. So it would be 1/8 + 1/7 = 1/15. Remember to only add the bottom numbers. not the top ones unless they are different colors or objects.
