3.305
+1.7
5.005
Line up the decimal points and add like you usually would add.
5.005 is the answer.
Answer:
a) To determine the minimum sample size we need to use the formula shown in the picture 1.
E is the margin of error, which is the distance from the limits to the middle (the mean) of the confidence interval. This means that we have to divide the range of the interval by 2 to find this distance.
E = 0.5/2 = 0.25
Now we apply the formula
n = (1.645*0.80/0.25)^2 = 27.7 = 28
The minimum sample size would be 28.
b) To answer the question we are going to make a 90% confidence interval. The formula is:
(μ - E, μ + E)
μ is the mean which is 127. The formula for E is shown in the picture.
E = 0.80*1.645/√8 = 0.47
(126.5, 127.5)
This means that the true mean is going to be contained in this interval 90% of the time. This is why it doesn't seem possible that the population mean is exactly 128.
An example of the ratio 4:1 could be, in a school for every 4 girls there is 1 boy. Or something similar:)
Hello there!
The number of people in different cities should be represented on a graph as Two-dimensional.
I'll explain why: The number of dimensions you need on a graph is equal to the number of variables that you are studying. In this case, you have two variables in the study:
1)The number of people
2)The city where they live
You'll need a two-dimensional graph with two axes in which one of the axes represents the number of people and the other axis represents the city. If you were also studying the age of those people, you'll need one more dimension to include this new variable.
Have a nice day!