Help pleaseee i am awful at math
2 answers:
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Answer:
We conclude that the valve does not perform to the specifications.
Step-by-step explanation:
We are given that the valve was tested on 120 engines and the mean pressure was 5.4 lbs/square inch. Assume the standard deviation is known to be 0.8.
If the valve was designed to produce a mean pressure of 5.6 lbs/square inch.
Let = <u><em>mean water pressure of the valve.</em></u>
So, Null Hypothesis, :
= 5.6 lbs/square inch {means that the valve perform to the specifications}
Alternate Hypothesis, :
5.6 lbs/square inch {means that the valve does not perform to the specifications}
The test statistics that would be used here <u>One-sample z test statistics</u> as we know about the population standard deviation;
T.S. = ~ N(0,1)
where, = sample mean pressure = 5.4 lbs/square inch
= population standard deviation = 0.8 5.4 lbs/square inch
n = sample of engines = 120
So, <u><em>the test statistics</em></u> =
= -2.738
The value of z test statistics is -2.738.
<u>Now, at 0.02 significance level the z table gives critical values of -2.3263 and 2.3263 for two-tailed test.</u>
Since our test statistic doesn't lie within the range of critical values of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which <u>we reject our null hypothesis</u>.
Therefore, we conclude that the valve does not perform to the specifications.
1. Felix’s sales are $53000. He has 3% of sales over $4800, then he has 3% of sales $(53000-4800)=$48200.
Now
$48200 -- 100%
$x -- 3%.
Write a proportion:
Thus, he additionally gets $1446.
2. If he earns $450 per week and earns $1446 of sales, then Felix earns
$450+$1446=$1896.
Answer: correct choice is A