Answer: (751.05, 766.95)
Step-by-step explanation:
We know that the confidence interval for population mean is given by :-
,
where 
=population standard deviation.
= sample mean
n= sample size
z* = Two-tailed critical z-value.
Given : 
n= 42
We know that from z-table , the two-tailed critical value for 99% confidence interval : z* =2.576
Now, the 99% confidence interval around the true population mean viscosity :-
![759\pm (2.5760)\dfrac{20}{\sqrt{42}}\\\\=759\pm (2.5760)(3.086067)\\\\=759\pm7.9497=(759-7.9497,\ 759+7.9497)\]\\=(751.0503,\ 766.9497)\approx(751.05,\ 766.95)](https://tex.z-dn.net/?f=759%5Cpm%20%282.5760%29%5Cdfrac%7B20%7D%7B%5Csqrt%7B42%7D%7D%5C%5C%5C%5C%3D759%5Cpm%20%282.5760%29%283.086067%29%5C%5C%5C%5C%3D759%5Cpm7.9497%3D%28759-7.9497%2C%5C%20759%2B7.9497%29%5C%5D%5C%5C%3D%28751.0503%2C%5C%20766.9497%29%5Capprox%28751.05%2C%5C%20766.95%29)
∴ A 99% confidence interval around the true population mean viscosity : (751.05, 766.95)
13 3/39 is too big, it's greater than 9, so that one is out.
16 is an integer, so that one is out too. 99/6 = 16.5, which is greater than 9, so it can't be right
So the answer is the other 3
Answer:
20 minutes
Step-by-step explanation:
The mean, or average of a data set can be found by adding all the values together, and dividing by the number of values.
The data set is: 20 minutes, 22 minutes and 18 minutes
1. Add the values together
Add all the numbers in the set together.
Data set: 20, 22, 18
Add them: 20+22+18
60
2. Divide by the number of values
Count how many numbers are in the set.
In this set, there are 3 numbers.
Divide 60 by 3
60/3 =20
20 minutes
His mean time is 20 minutes.
The correct answer for this problem is it has infinity solutions. Both equations equal up to t=5 -1/2
The right method to use in order to represent the numerical data on the vertical axis of a Bar Chart is 0 to 40.
<h3>How do you set the vertical axis of a Bar Chart?</h3>
In setting the vertical axis of a Bar Chart, note that it is vital for the categories to be natural as possible.
That is, the vertical axis should always begin with the number zero (0) and the scale values for the x axis must range from the lowest value on the left hand side to highest on the right hand side.
Therefore, due to the explanation given, the right method to use in order to represent the numerical data on the vertical axis of a Bar Chart is 0 to 40 as it range from 0 to the highest value.
Learn more about Bar Chart from
brainly.com/question/24741444
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