Help me out thank you. use the image I have attached.
2 answers:
You might be interested in
Answer:
And if we solve for a we got
And for this case the answer would be 35185 the lowest 1% for the salary
Step-by-step explanation:
Let X the random variable that represent the salary, and for this case we can assume that the distribution for X is given by:
Where and
And we want to find a value a, such that we satisfy this condition:
(a)
(b)
We can use the z score again in order to find the value a.
As we can see on the figure attached the z value that satisfy the condition with 0.01 of the area on the left and 0.99 of the area on the right it's z=-2.33. On this case P(Z<-2.33)=0.01 and P(z>-2.33)=0.99
If we use condition (b) from previous we have this:
But we know which value of z satisfy the previous equation so then we can do this:
And if we solve for a we got
And for this case the answer would be 35185 the lowest 1% for the salary
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.