Question

The quality manager at Bestiful Company is certifying a new process that must produce 95% (or better) good product before the process is considered proven. A sample of 40 containers from the process line are tested, and 93% are found to be good. (a) Formulate the appropriate hypotheses and test them using an α = 0.01 significance level. (b) Explain your results.

284

likes
1420 views

Answer to a math question The quality manager at Bestiful Company is certifying a new process that must produce 95% (or better) good product before the process is considered proven. A sample of 40 containers from the process line are tested, and 93% are found to be good. (a) Formulate the appropriate hypotheses and test them using an α = 0.01 significance level. (b) Explain your results.

Expert avatar
Dexter
4.7
113 Answers
Let's define the hypotheses for this hypothesis test:
- Null Hypothesis (H0): The proportion of good products produced by the new process is equal to 95%.
- Alternative Hypothesis (H1): The proportion of good products produced by the new process is less than 95%.

Given that the sample size is large (n = 40) and the sample proportion of good products is p̂ = 0.93, we can use the normal approximation to the binomial distribution to conduct a hypothesis test using a z-test.

(a) Test the hypotheses using a significance level of α = 0.01.
The test statistic formula for a z-test is:
z = \frac{p̂ - p}{\sqrt{\frac{p(1-p)}{n}}}
where p is the hypothesized population proportion (0.95 in this case).

Plugging in the values:
z = \frac{0.93 - 0.95}{\sqrt{\frac{0.95(1-0.95)}{40}}}
z = \frac{-0.02}{\sqrt{\frac{0.95*0.05}{40}}}
z = \frac{-0.02}{\sqrt{\frac{0.0475}{40}}}
z = \frac{-0.02}{\sqrt{0.0011875}}
z = \frac{-0.02}{0.03446}
z = -0.58

Next, we find the critical z-value for a one-tailed test at α = 0.01 by looking up the z-value in the standard normal distribution table or using a calculator: z_{\alpha = 0.01} = -2.33

(b) Conclusion:
Since our calculated z-value (-0.58) does not fall in the rejection region (less than -2.33), we do not reject the null hypothesis.
Therefore, there is not enough evidence to conclude that the proportion of good products produced by the new process is less than 95%.

\boxed{Answer: \text{The null hypothesis is not rejected. The process is proven to produce 95\% or more good products.}}

Frequently asked questions (FAQs)
Question: What is the formula used to calculate the standard deviation of a data set?
+
What is the quadratic formula and how can it be applied to solve equations?
+
What is the equation for an ellipse with a major axis of length 6 and a minor axis of length 4?
+
New questions in Mathematics
8x²-30x-10x²+70x=-30x+10x²-20x²
The patient is prescribed a course of 30 tablets. The tablets are prescribed “1 tablet twice a day”. How many days does a course of medication last?
How do you think the company has increased or decreased its income?
Consider numbers from 1 to 2023. We delete 3 consecutive numbers so, that the avarage of the left numbers is a whole number
(5u + 6)-(3u+2)=
A regional candy factory sells a guava roll at a price of $48, the monthly fixed costs amount to $125,000 and the variable cost for making a guava roll is $28. Determine: a) The equation of the total income from the production of guava rolls.
A company that manufactures personal hygiene items purchases machinery for $220,000 that is considered to last 7 years; it is estimated that at the end of the period it will have a salvage value of $1000. Find: to. The depreciation rate. b. The book value at the end of the sixth year.
A person borrows rm 1000 from a bank at an interest rate of 10%. After some time, he pays the bank rm 1900 as full and final settlement of the loan. Estimate the duration of his loan.
15/5+7-5
Raúl, Gilberto and Arturo are playing golf; The probabilities of winning for each one are as follows: (Raúl wins) = 20% (Gilberto wins) = 0.05% (Arturo wins) = ¾%. Perform operations and order events from least to most probable.
The price per night of a suite at the Baglioni Hotel in Venice is 1896 euros, VAT included. The VAT in Italy is 25%. The hotel gets a return of 10% out of the price VAT included. a) What is the amount of VAT paid by the hotel for one
Given (3x+2)E [2;14] how much money (in soles) does Sophia have if numerically it is the greatest value of x?
I. Order to add 40.25+1.31+.45 what is the first action to do ?
3/9*4/8=
Use linear approximation to estimate the value of the sine of 31o.
-1%2F2x-4%3D18
Find the minimum value of the function y = -4 x3 + 60 x2 -252 x + 8 for values of x between x = 0 and x = 9 Enter the value of the function, not the value of x
We have two distributions: A (M = 66.7, 95% CI = [60.3, 67.1]) / B (M = 71.3 95% CI = [67.7, 74.9]). Erin maintains that B is significantly larger than A. Provide your opinion on Erin’s argument and justify your opinion.
Consider the function f(x)=1/2(x+1)^2-3. Use the preceding/following interval method to estimate the instantaneous rate of change at 𝑥 = 1.
Question 3 A square has a perimeter given by the algebraic expression 24x – 16. Write the algebraic expression that represents one of its sides.