Answer:
∠ CED = 58°
Step-by-step explanation:
∠ CED and ∠ AED are adjacent angles and sum to 180° , then
∠ CED + 122° = 180° ( subtract 122° from both sides )
∠ CED = 58°
Answer:
12
Step-by-step explanation:
(5/25)(15/24)
For this, you have to understand the ratios of a 30,60,90 triangle. The ratio(in order) is x, x(sqrt 3), 2x (following the 30,60,90 pattern y'know). Well, we know the length of the hypotenuse, 4.2, so let's use ratios to figure the other sides out. The ratio of AC is x and the ratio of AB is 2x, so 2x/2=x=2.1. One side down. BC has a ratio of x(sqrt 3). We already know x so we can substitute it in. We get 2.1(sqrt 3). To calculate the area, use the formula 1/2(bh). Inputting the values in, we get 1/2(2.1*(2.1(sqrt 3)). This can be calculated to around 3.82. To calculate the perimeter, take the sum of the sides. By adding the sides together, we get about 9.98. Hope you can now understand how to do these kinds of questions.
Answer:
So then the minimum sample to ensure the condition given is n= 38
Step-by-step explanation:
Notation
represent the sample mean for the sample
population mean (variable of interest)
represent the population standard deviation
n represent the sample size
ME = 4 the margin of error desired
Solution to the problem
When we create a confidence interval for the mean the margin of error is given by this formula:
(a)
And on this case we have that ME =4 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
The critical value for 96% of confidence interval now can be founded using the normal distribution. The significance is 
. And in excel we can use this formula to find it:"=-NORM.INV(0.02;0;1)", and we got 
, replacing into formula (b) we got:
So then the minimum sample to ensure the condition given is n= 38
