We need to find out how many adults must the brand manager survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage.
From the given data we know that our confidence level is 90%. From Standard Normal Table we know that the critical level at 90% confidence level is 1.645. In other words,
.
We also know that E=5% or E=0.05
Also, since,
is not given, we will assume that
=0.5. This is because, the formula that we use will have
in the expression and that will be maximum only when
=0.5. (For any other value of
, we will get a value less than 0.25. For example if,
is 0.4, then
and thus,
.).
We will now use the formula

We will now substitute all the data that we have and we will get



which can approximated to n=271.
So, the brand manager needs a sample size of 271
Answer:
1. Her time in minutes is 720/s minutes
2. Given her time to be 20 minutes, her speed is 36 mph
Step-by-step explanation:
Mathematically,
Distance = speed * time
In this question, we want to calculate time;
So time = distance/speed
times = 12 miles/s mph = 12/s hours
Now we want our answer in minutes
Kindly recall that 60 minutes = 1 hour
So 12/s hours will be 12/s * 60 = 720/s minutes
2. Since she drives from home to the office in in 20 minutes, we want to calculate her speed in mph
From the time calculated above i.e 720/s
We can equate 20 = 720/s
20s = 720
s = 720/20
s = 36 mph
According to the question,
Let,
"n" represent the number of miles semir walked.
"y" represent the number of miles sarah walked.
Now, according to the question,
y = 2n - 5 ........................this is your equation
Also,
the question states, each of them collect $18 in pledges for every miles walked.
Given,
Sarah collected $450
Now,
Using unitary method,
Sarah collects $18 for 1 mile
Sarah collects $1 for (1 / $18) mile
Sarah collects $450 for (1 / 18) * 450 mile
= 25 miles
So, Sarah walks 25 miles.
Now,
Taking equation,
y = 2n - 5
Since, y is the no. of miles sarah walked, we can write 25 in place of "y" So,
(25) = 2n - 5
25 + 5 = 2n
30 = 2n
30 / 2 = n
15 = n
Since, "n" is the no. of miles that semir walked, Semir walked 15 miles.
Sorry but I don’t understand your language.
Answer:
x = 25
Step-by-step explanation:
Angle 1 and the angle opposite from Angle 1 (the angle that's 68°) are vertical angles.
What are vertical angles, you ask?
According to the Oxford dictionary, vertical angles are each of the pairs of opposite angles made by two intersecting lines.
For example, take the letter X. The letter X has two lines that intersect to form 4 angles. The top and bottom angles are a pair of vertical angles. So are the left and right angles.
Vertical angles are always congruent.
(This is VERY important to know! It will help you solve many types of geometry problems!)
m1 is 3x - 7. Because Angle 1 and the angle that's 68° are vertical angles, that means they are equal to each other.
Therefore: 3x - 7 = 68.
Now, you can solve for x to get x = 25.
Hope this helps!