Find a 95% confidence interval for the mean failure pressure for this type of roof panel.The article "Wind-Uplift Capacity of Re
1 answer:
Answer:
The 95% confidence interval would be given by (2.351;3.525)
Explanation:
1) Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
represent the sample mean
population mean (variable of interest)
s represent the sample standard deviation
n represent the sample size
2) Confidence interval
The confidence interval for the mean is given by the following formula:
(1)
In order to calculate the mean and the sample deviation we can use the following formulas:
(2)
(3)
The mean calculated for this case is
The sample deviation calculated
In order to calculate the critical value we need to find first the degrees of freedom, given by:
Since the Confidence is 0.95 or 95%, the value of and
, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,4)".And we see that
Now we have everything in order to replace into formula (1):
So on this case the 95% confidence interval would be given by (2.351;3.525)
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Answer:
I am writing a Python program that deletes players from the file whose names whose names do not begin with a vowel which means their names begin with a consonant instead. Since the SomePlayers.txt is not provided so i am creating this file. You can simply use this program on your own file.
fileobj= open('SomePlayers.txt', 'r')
player_names=[name.rstrip() for name in fileobj]
fileobj.close()
vowels = ('a', 'e', 'i', 'o', 'u','A','E','I','O','U')
player_names=[name for name in player_names
if name[0] in vowels]
fileobj.close()
print(player_names)
Explanation:
I will explain the program line by line.
First SomePlayers.txt is opened in r mode which is read mode using open() method. fileobj is the name of the file object created to access or manipulate the SomePlayers.txt file. Next a for loop is used to move through each string in the text file and rstrip() method is used to remove white spaces from the text file and stores the names in player_names. Next the file is closed using close() method. Next vowels holds the list of characters which are vowels including both the upper and lower case vowels.
player_names=[name for name in player_names
if name[0] in vowels]
This is the main line of the code. The for loop traverses through every name string in the text file SomePlayers.txt which was first stored in player_names when rstrip() method was used. Now the IF condition checks the first character of each name string. [0] is the index position of the first character of each players name. So the if condition checks if the first character of the name is a vowel or not. in keyword is used here to check if the vowel is included in the first character of every name in the file. This will separate all the names that begins with a vowel and stores in the list player_names. At the end the print statement print(player_names) displays all the names included in the player_names which begin with a vowel hence removing all those names do not begin with a vowel.
