Answer:
He must survey 123 adults.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of 
.
The margin of error is:
Assume that a recent survey suggests that about 87% of adults have heard of the brand.
This means that 
90% confidence level
So 
, z is the value of Z that has a p-value of 
, so 
.
How many adults must he survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage?
This is n for which M = 0.05. So
Rounding up:
He must survey 123 adults.
Answer:
8 square units
Step-by-step explanation:
The figure is a trapezoid. The area of it is given by the formula ...
A = (1/2)(b1 +b2)h
where b1 and b2 are the lengths of the parallel bases and h is the distance between them.
Your figure shows the base lengths to be 5 and 3, and their separation to be 2. Filling the numbers in the formula, we have ...
A = (1/2)(5 +3)(2) = (1/2)(8)(2) = 4·2 = 8
The area of the figure is 8 square units.
_____
The right-pointing arrows on the horizontal lines identify those lines as being parallel. The right-angle indicator and the 2 next to the dotted line indicate the perpendicular distance between the parallel lines is 2 units.
This theorem says that the exterior angle is equal to the sum of its remote interior angles. In other words, 140 = 2x + x + 2. 140 = 3x + 2 and 138 = 3x. Therefore, x = 46. Multiply it by 2 to get angle B is 92 degrees.
Your teacher just wants you to replace pi any equations with 22/7 because it is close to pi
Answer:250 kilometers
Step-by-step explanation:
so it travels 100 kilometers north and another 150 kilometers north so 100+150 is 250 kilometers
