E.J. calls people at random to conduct a survey. So far, 40 calls have been
2 answers:
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Answer:
P(X 74) = 0.3707
Step-by-step explanation:
We are given that the score of golfers for a particular course follows a normal distribution that has a mean of 73 and a standard deviation of 3.
Let X = Score of golfers
So, X ~ N()
The z score probability distribution is given by;
Z = ~ N(0,1)
where, = population mean = 73
= standard deviation = 3
So, the probability that the score of golfer is at least 74 is given by = P(X 74)
P(X 74) = P(
) = P(Z
0.33) = 1 - P(Z < 0.33)
= 1 - 0.62930 = 0.3707
Therefore, the probability that the score of golfer is at least 74 is 0.3707 .
Answer:
Null hypothesis:
Alternative hypothesis:
Step-by-step explanation:
1) Data given and notation
n=1500 represent the random sample taken
X represent the number of graduates that had student loan debt in 2014
estimated proportion of adults that said that it is morally wrong to not report all income on tax returns
is the value that we want to test
represent the significance level
z would represent the statistic (variable of interest)
represent the p value (variable of interest)
2) Concepts and formulas to use
We need to conduct a hypothesis in order to test the claim that if there was a significant increase in the proportion of student loan debt for public and nonprofit colleges in 2014 respect to the value of 2013.:
Null hypothesis:
Alternative hypothesis:
When we conduct a proportion test we need to use the z statistic, and the is given by:
(1)
The One-Sample Proportion Test is used to assess whether a population proportion is significantly different from a hypothesized value
.
3) Calculate the statistic
Since we have all the info requires we can replace in formula (1) like this:
4) Statistical decision
It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.
The significance level assumed is . The next step would be calculate the p value for this test.
Since is a right tailed test the p value would be:
If we compare the p value obtained and using the significance level assumed we have
so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of adults that said that it is morally wrong to not report all income on tax returns is not significantly higher than 0.69.