The coordinate plane shows the floor plan for a swimming pool. What is the area of the pool’s border? A. 50 square meters B. 65
1 answer:
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If there are real roots to be found for this polynomial, the Rational Root Theorem and synthetic division are the best way to find them. I teach from a book that uses c and d for the possible roots of the polynomial. C is our constant, 2, and d is the leading coefficient, 1. The factors of 2 are +/- 1 and +/-2. The factors for 1 are +/-1 only. Meaning, in all, there are 4 possibilities as roots for this polynomial. But there are only 3 total (because our polynomial is a third degree), so we have to find the first one, at least, from our possibilities above. Let's try x = -1, factor form (x + 1). If there is no remainder when we do the synthetic division, then -1 is a root. Put -1 outside the "box" and the coefficients from the polynomial inside: -1 (1 2 -1 -2). Bring down the first coefficient of 1 and multiply it by the -1 outside to get -1. Put that -1 up under the 2 and add to get 1. Multiply 1 times the -1 to get -1 and put that -1 up under the -1 and add to get -2. -1 times -2 is 2, and -2 + 2 = 0. So we have our first root of (x+1). The numbers we get when we do the addition along the way are the coefficients of our new polynomial, the depressed polynomial (NOT a sad one cuz it hates math, but a new polynomial that is one degree less than that of which we started!). The new polynomial is 
. That can also be factored to find the remaining 2 roots. Use standard factoring to find that the other 2 solutions are (x+2) and (x-1). Our solutions then are x = -2, -1, 1, choice B from above.
Answer:
We conclude that the new procedure will not decrease the population mean amount of time required to produce the part.
Step-by-step explanation:
We are given that a large manufacturing plant has analyzed the amount of time required to produce an electrical part and determined that the times follow a normal distribution with mean time μ = 45 hours.
A random sample of 25 parts will be selected and the average amount of time required to produce them will be determined. The sample mean amount of time is = 43.118 hours with the sample standard deviation s = 5.5 hours
<em>Let </em><em> = population mean amount of time required to produce an electrical part using new procedure</em>
SO, <u>Null Hypothesis</u>, :
45 hours {means that the new procedure will remain same or increase the population mean amount of time required to produce the part}
<u>Alternate Hypothesis,</u> :
< 45 hours {means that the new procedure will decrease the population mean amount of time required to produce the part}
The test statistics that will be used here is <u>One-sample t test statistics </u>because we don't know about the population standard deviation;
T.S. = ~
where, = sample mean amount of time = 43.118 hours
s = sample standard deviation = 5.5 hours
n = sample of parts = 25
So, <u><em>test statistics</em></u> = ~
= -1.711
<em>Now at 0.025 significance level, the t table gives critical value of -2.064 at 24 degree of freedom for left-tailed test. Since our test statistics is more than the critical value of t so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region.</em>
Therefore, we conclude that the new procedure will remain same or increase the population mean amount of time required to produce the part.