Answer:
The confidence level is 0.98 and the significance is 
and 
and the critical value using the table is:
And replacing we got:
Step-by-step explanation:
For this case we have the following info given:
represent the population deviation
the sample size
represent the sample mean
We want to find the margin of error for the confidence interval for the population mean and we know that is given by:
The confidence level is 0.98 and the significance is and and the critical value using the table is:
And replacing we got:
Answer:
Step-by-step explanation:
The area of a circle is A = πr², where r is the radius. That means in order to solve this we have to find the value of x, which is the diameter of the lake, and then divide it in half to get the radius. To find x we will use similar triangles and proportions. x is the height of the big triangle and 4.5 is the height of the smaller triangle; 15.3 + 7.4 is the hypotenuse of the big triangle and 7.4 is the hypotenuse of the smaller triangle. Setting up our proportion:
which simplifies a bit to
and cross multiply to solve for x:
7.4x = 102.15 so
x = 13.8 That is the diameter of the lake. Divide it in half to get 6.9, the radius. Applying the area formula for a circle:
A = (3.14)(6.9)² and
A = 3.14(47.61) so
A = 149.5 which rounds to 150, Choice C
Answer:
it's C.
Step-by-step explanation:
Hope that helped :D
Answer:
Step-by-step explanation:
the first one is correct
