In which number does the 5 represent a value 100 times the value represented by the 5 in 35,187?
2 answers:
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:
0.0073 < 0.05, which means that we reject the null hypothesis and conclude that the true proportion of interest is higher than 0.7.
Step-by-step explanation:
Conduct a test to determine whether the true proportion of interest is higher than 0.7.
This means that the null hypothesis is:
And the alternate hypothesis is:
The test statistic is:
In which X is the sample mean, is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
0.7 is tested at the null hypothesis:
This means that
The sociologist found that 375 of the 500 travelers randomly selected and interviewed indicated that the airports were safe.
This means that
Value of the z-statistic:
P-value of the test:
Probability of z being larger than 2.44, that is, a proportion larger than 0.75.
This is, looking at the z-table, 1 subtracted by the pvalue of Z = 2.44. S
Z = 2.44 has a pvalue of 0.9927
1 - 0.9927 = 0.0073
0.0073 < 0.05, which means that we reject the null hypothesis and conclude that the true proportion of interest is higher than 0.7.