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
114 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)
What is the surface area of a cone with radius 4 cm and height 10 cm?
+
What is the probability of rolling a six-sided die and getting an odd number?
+
What is the area of a right triangle with base = 8 cm and height = 6 cm?
+
New questions in Mathematics
Using a remarkable product you must factor the expression: f(x) =36x^2-324 and you are entitled to 5 steps
two pails of different sizes contain 34.5 litres of water altogether When 0.68 litre of water is poured from the bigger pail into the smaller pail the amount of water in the bigger pail is 9 times that in the smaller pail. How much water was in the smaller pail at first?
How do you think the company has increased or decreased its income?
You have been hired to estimate the average weight of quarters in circulation. Based on the sample of quarters you collect (below), create a 90% confidence interval for the weight of quarters in circulation. Quarter Weights (grams) 5.631 5.714 5.719 5.689 5.551 5.723 5.705 5.627 5.627 5.715 5.576 5.632 5.641 5.676 5.660 5.699 5.609 5.634 5.713 5.591 5.674 5.675 5.684 5.694 5.655 5.632 5.598 5.675 5.628 5.562 5.636 5.583 5.567 5.551 5.649 5.708 5.696 5.614 5.637 5.601 5.628 5.711 5.566 5.653 5.653 5.597 5.687 5.717 5.678 5.654 5.556 5.707 5.563 5.628 5.679 5.714 5.555 5.719 5.634 5.647 5.717 5.612 5.705 5.657 5.670 5.607 5.687 5.666 5.612 5.718 5.714 5.713 5.663 5.641 5.589 5.656 5.712 5.639 5.577 5.580 5.674 5.636 5.625 5.597 5.616 5.591 5.616 5.700 5.706 5.695 5.562 5.699 5.607 5.573 5.659 5.632 5.654 5.568 5.628 5.687 5.605 5.689 5.687 5.554 5.618 5.701 5.681 5.645 5.714 5.665 5.661 5.634 5.714 5.586 5.656 5.673 5.657 5.717 5.611 5.578 5.579 5.614 5.644 5.724 5.647 5.566 5.697 5.558 5.586 5.586 5.611 5.573 5.573 5.709 5.629 5.649 5.552 5.615 5.645 5.611 5.686 5.588 5.641 5.704 5.703 5.696 5.557 5.551 5.725 5.608 5.725 5.603 5.677 5.638 5.573 5.640 5.561 5.631 5.563 5.671 5.662 5.569 5.648 5.680 5.681 5.551 5.555 5.578 5.701 5.645 5.670 5.574 5.594 5.705 5.633 5.719 5.680 5.647 5.641 5.553 5.616 5.698 5.552 5.566 5.559 5.697 5.686 5.560 5.629 5.701 5.622 5.615 5.553 5.608 5.637 5.663 5.696 5.714 5.675 5.613 5.594 5.669 5.569 5.716 5.705 5.603 5.709 5.717 5.606 5.581 5.575 5.601 5.600 5.664 5.715 5.705 5.583 5.586 5.592 5.550 5.628 5.662 5.603 5.559 5.676 5.558 5.678 5.671 5.642 5.581 5.568 5.706 5.665 5.712 5.574 5.602 5.699 5.716 5.693 5.711 5.635 5.612 BLANK #1: Is this a question involving mean or proportion? ***ANSWER "MEAN" OR "PROPORTION" (WITHOUT THE QUOTATION MARKS)*** BLANK #2: What is the LOW end of the estimate ***ANSWER TO 3 DECIMALS*** BLANK #3: What is the HIGH end of the estimate ***ANSWER TO 3 DECIMALS***
In a store, a person carries 14 kilos of rice and 28 kilos of flour. In what ratio are the kilos found? (Remember to simplify until you reach an irreducible fraction)
calculate the normal vector of line y = -0.75x + 3
The durability of a tire of a certain brand is a Normal random variable with an average of 64,000 km and a standard deviation of 9,000 km. Assuming independence between tires, what is the probability that the 4 tires on a car will last more than 58,000 km?
(24, -7) is on the terminal arm of an angle in standard position. Determine the exact values of the primary trigonometric functions.
The sum of two numbers is 144. Double the first number minus thrice the second number is equal to 63. Determine the first two numbers.
suppose random variable x follows poisson distribution with expected value 3. what is variance of x?
Buffalo Company makes and sells shampoo. Each unit requires $1.40 labor costs, material costs per unit are $0.90 and other variable costs are $0.30. It sells shampoo for $4.45 to retailers. Fixed costs are $15,000. It sold 25,000 units in the current month. What is the Break-Even point in units? What is the Break-Even point in dollars? What is the contribution margin of Buffalo Company?
Fill in the P(X-x) values to give a legitimate probability distribution for the discrete random variable X, whose possible values are -5 ,3 , 4, 5 , and 6.
7.57 Online communication. A study suggests that the average college student spends 10 hours per week communicating with others online. You believe that this is an underestimate and decide to collect your own sample for a hypothesis test. You randomly sample 60 students from your dorm and find that on average they spent 13.5 hours a week communicating with others online. A friend of yours, who offers to help you with the hypothesis test, comes up with the following set of hypotheses. Indicate any errors you see. H0 :x ̄<10hours HA : x ̄ > 13.5 hours
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.
Determine the kinetic energy of a baseball whose mass is 100 grams and has a speed of 30 m/s.
A 20,000 kg school bus is moving at 30 km per hour on a straight road. At that moment, it applies the brakes until it comes to a complete stop after 15 seconds. Calculate the acceleration and the force acting on the body.
Solve the following 9x - 9 - 6x = 5 + 8x - 9
For how long does the principal amount of €7,537 bring the same interest as the principal amount of €12,345 invested for 8 months? Interest calculation is simple and decursive.
question 1 Consider a sample space S, and two events A and B such that P(A ∩ B) = 0.2, P(A ∪ B) = 0.6, P(B ∪ ̄A) = 0.8 (a) [0.5 points] Calculate P (A). (b) [0.5 points] Calculate P (B)
Define excel and why we use it?