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)
Simplify the fraction 2 1/2 + 3 3/4 and express the result as a mixed number.
+
Math question: Find the slope-intercept equation of the line passing through points A(2, 3) and B(-4, 1).
+
Math Question: Solve log(base 2) x + log(base 2) 8 = log(base 2) 128. Compute the value of x. (
+
New questions in Mathematics
Find 2 numbers that the sum of 1/3 of the first plus 1/5 of the second will be equal to 13 and that if you multiply the first by 5 and the second by 7 you get 247 as the sum of the two products with replacement solution
Convert the following function from standard form to vertex form f(x) = x^2 + 7x - 1
-x+3x-2,si x=3
10! - 8! =
5(4x+3)=75
what is 9% of 307
Given that y = ×(2x + 1)*, show that dy = (2x + 1)" (Ax + B) dx where n, A and B are constants to be found.
x/20*100
4x-3y=5;x+2y=4
the probabilty that a person has a motorcycle, given that she owns a car 25%. the percentage of people owing a motorcycle is 15% and that who own a car is 35%. find probabilty that a person owns any one or both of those
Determine the general equation of the straight line that passes through the point P (2;-3) and is parallel to the straight line with the equation 5x – 2y 1 = 0:
Jasminder has made 55% of the recipes in a particular cookbook. If there are 9 recipes that he has never made, how many recipes does the cookbook contain?
cube root of 56
How to convert 45 kg into grams
A diamond ring was reduced from $999.99 to $689.99. Find the percent reduction in the price. Round the answer to the nearest tenth of a percent, if necessary.
Total Users with an active Wise account = Total Active Users + Total Users who haven’t transacted Total Active Users = Total MCA Users + Total Send Users = Total New Users + Retained Users Total New Users = New Send Users + New MCA Users Total MCA Users = New MCA Users + Retained Users who transacted this month via MCA Total Send Users = New Send Users + Retained Users who transacted this month via Send Send CR = Total Send Users / Total Users with an active Wise account MCA CR = Total MCA Users / Total Users with an active Wise account New Send CR = New Send Users / New Profiles Created in Month New MCA CR = New MCA Users / New Profiles Created in Month We have recently witnessed a drop in MCA conversion, but send user conversion is stable, can you help explain why?
In a school playground When going out for recess, 80 men and 75 women coexist, the Patio measures 10 meters For 40 meters (what will be the population density in the break
Dano forgot his computer password. The password was four characters long. Dano remembered only three characters: 3, g, N. The last character was one of the numbers 3, 5, 7, 9. How many possible expansions are there for Dano's password?
5 1/9 + 2 2/3
Construct a set of six pieces of data with​ mean, median, and midrange of 67 and where no two pieces of data are the same.