Please answer the question and provide a solid definition of what an expression is, thank you :)
1 answer:
You might be interested in
Answer:
For every 1000 pairs sold, the manufacturer expect to replace 239 pairs for free.
Step-by-step explanation:
Given:
Mean (μ) = 2.2, Standard deviation(S.D) (σ) = 1.7 years and x = 1 (1 year)
Let's find the Z score.
Z =
Now plug in the given values in the above formula, we get
Z =
Now we have to use the z-score table.
The z-score for 0.71 is 0.2611
Since it z is negative, so we subtract 0.2611 from 0.5000
0.5000 - 0.2611 = 0.2389
Percentage = 0.2389 × 100 = 23.89%
To find replaces for 1000 pairs, we need to multiply 23.89% by 1000
=
= 239
The cannot be in decimal, when we round off to the nearest whole, we get
239
Answer:
If we compare the p value and the significance level given we see that
so we can conclude that we have enough evidence to reject the null hypothesis,and we have enough evidence to conclude that the true mean is significantly lower thn 4.8 at 10% of signficance.
Step-by-step explanation:
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)
State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if thetrue mean is below the specifications, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
If we analyze the size for the sample is > 30 and we know the population deviation so 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".
Calculate the statistic
We can replace in formula (1) the info given like this:
P-value
Since is a one sided test the p value would be:
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 reject the null hypothesis,and we have enough evidence to conclude that the true mean is significantly lower thn 4.8 at 10% of signficance.