Please show full solutions! Will mark brainliest for the best answers! Thanks. Question is attached!
1 answer:
9514 1404 393
9514 1404 393
Answer:
a) P = -28(x -112)² +7500
b) $102.55 or $121.45
Step-by-step explanation:
a) A quadratic relation with a maximum of 7500 at x=112 can be written in vertex form as ...
P = a(x -112)² +7500
The other given point (x, P) = (89, -7312) can be used to find the value of 'a'.
-7312 = a(89 -112)² +7500
-14812 = a(529)
a = -14812/529 = -28
So, the desired quadratic relation is ...
P = -28(x -112)² +7500
__
b) The values of x that make P = 5000 can be found from ...
5000 = -28(x -112)² +7500
-2500 = -28(x -112)² . . . . . . . . subtract 7500
89.286 = (x -112)² . . . . . . . . . . . divide by -28
±9.45 = x -112 . . . . . . . . . . take the square root
x = 112 ± 9.45 = {102.55, 121.45}
Setting the price at about $102.55, or $121.45, will yield a profit of $5000.
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Answer:
Null hypothesis:
Alternative hypothesis:
If we compare the p value and the significance level given we see that
so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so then we can conclude that the mean pressure for the automobile engines is not significantly less than 7.3 at 1% of significance.
Step-by-step explanation:
1) Data given and notation
represent the sample mean
represent the population standard deviation
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
z would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
2) State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if the mean pressure is lower than the specificated value 7.3, the system of hypothesis are :
Null hypothesis:
Alternative hypothesis:
Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:
(1)
z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".
3) Calculate the statistic
We can replace in formula (1) the info given like this:
4) P-value
Since is a one-side lower test the p value would given by:
5) Conclusion
If we compare the p value and the significance level given we see that
so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the mean pressure for the automobile engines is not significantly less than 7.3 at 1% of significance.