please give step by step answers...draw the slope.... if using the computer plea

Question

please give step by step answers...draw the slope.... if using the computer please show how you used excel with the slope.
Thank you

Question 4 (Hinti Z statistics) (25 points) The quality control manager at a light bulb factory needs to estimate the average life of a large shipment of light bulbs. The process standard deviation is known to be 100 hours. A random sample of 64 light bulbs indicates a sample average of 350 hours. a) State the null and alternate hypothesis b) At the 0.05 level of significance is there evidence that the average life is different from 385 hours c) At the 0.10 level of significance is there evidence that the average life is greater than 385? Also restate the null and alternate hypothesis

Explanation / Answer

(a) Null Hypothesis H0: The average life of a large shipment of light bulbs is equal to 385 hours.
Alternative Hypotheis H1: The average life of a large shipment of light bulbs is not equal to 385 hours.

(b) Sample standard deviation = 100/sqrt(64) = 100/8 = 12.5
Z = (Observed - Hypothesized)/Sample standard deviation
= (350-385)/12.5 = -2.8
P(Z < -2.8) = 0.0026
For two-tail test, p = 2 * 0.0026 = 0.0052
As, the p-value is less than the significance level of 0.05, we reject the null hypothesis and conclude that there is evidence that the average life of a large shipment of light bulbs is not equal to 385 hours.

(c) Null Hypothesis H0: The average life of a large shipment of light bulbs is less than 385 hours.
Alternative Hypotheis H1: The average life of a large shipment of light bulbs is greater than 385 hours.
Z = (Observed - Hypothesized)/Sample standard deviation
= (350-385)/12.5 = -2.8
P(Z > -2.8) = 0.9974
As, the p-value is greater than the significance level of 0.10, we fail to reject the null hypothesis and conclude that there is not enough evidence that the average life of a large shipment of light bulbs is greater than 385 hours

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.