Please help me ,thank you !
2 answers:
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Answer:
x = -4
x = -1
Step-by-step explanation:
We have been given the following quadratic equation;
x^2 + 5x + 4 = 0
We are required to determine the roots of the above quadratic equation via graphing.
To do this we formulate the following equations;
y = x^2 + 5x + 4
y = 0 (x -axis)
We then proceed to graph these functions on the same graph. The roots of the original quadratic equation will be the points where the graphs of the above functions will intersect.
The attachment below is the graphical solution obtained from desmos graphing tool;
The graph of the functions intersect at;
x = -4 and x = -1
These are the roots of the given quadratic equation
Answer:
B. 0.2061
Step-by-step explanation:
1) Data given and notation
n=380 represent the random sample taken
X=19 represent the no-shows in the sample
estimated proportion of no-shows in the sample
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 the no-show rate for passengers booked on its flights is less than 6%:
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 next step would be calculate the p value for this test.
Since is a one left tailed test the p value would be:
So the p value obtained was a very high value and using the significance level for example we have
so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the proportion of no-show rate for passengers booked on the company flights is nor significantly less than 0.06 or 6%.