You will need 100 feet of fencing to put all the way around a rectangular garden. The length of the garden is 30 feet. What is t
1 answer:
You might be interested in
Answer:
Confidence Interval - 2.290 < S < 2.965
Step-by-step explanation:
Complete question
A chocolate chip cookie manufacturing company recorded the number of chocolate chips in a sample of 50 cookies. The mean is 23.33 and the standard deviation is 2.6. Construct a 80% confidence interval estimate of the standard deviation of the numbers of chocolate chips in all such cookies.
Solution
Given
n=50
x=23.33
s=2.6
Alpha = 1-0.80 = 0.20
X^2(a/2,n-1) = X^2(0.10, 49) = 63.17
sqrt(63.17) = 7.948
X^2(1 - a/2,n-1) = X^2(0.90, 49) = 37.69
sqrt(37.69) = 6.139
s*sqrt(n-1) = 18.2
confidence interval:
(18.2/7.948) < S < (18.2/6.139)
2.290 < S < 2.965
Answer:
Top 5% is 5.84 milliters and the bottom 5% is 5.60 millimeters.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
Top 5%:
X when Z has a pvalue of 0.95. So X when Z = 1.645
Bottom 5%:
X when Z has a pvalue of 0.05. So X when Z = -1.645
Top 5% is 5.84 milliters and the bottom 5% is 5.60 millimeters.