A sample of 87 glass sheets are measured for thickness. They have a sample mean of 4.20 mm and a sample standard deviation of 0.10 mm. What is the level of the confidence interval (4.185, 4.215)?

83.85%

Step-by-step explanation:

The formula for confidence interval

= Mean ±( z × Standard deviation/√n)

Confidence Interval = Mean ± Margin of Error

Mean = 4.20mm

n = 87

Standard deviation = 0.10mm

z =

Hence:

Confidence Interval = Mean ± Margin of Error

Step 1

We find the Margin of Error

(4.185, 4.215) = 4.20 ± Margin of Error

4.20 - 4.185 = 0.015

4.215 - 4.20 = 0.015

Hence, Margin of Error = ± 0.015

Step 2

We find the z score

Margin of Error = z × Standard deviation/√n

±0.015 = z × 0.10/√87

± 0.015 = 0.0107211253z

z = ±0.015/0.0107211253

z = 1.39910686428

z score ≈ 1.4

Step 3

We find the confidence interval that corresponds to 1.4

Using the z table to find the Probability

P(z = 1.4) = 83.85%

Therefore, the level of the confidence interval (4.185, 4.215) is 83.85%

answer: b. f(x) = (x + 2)^3 (x^2 - 7x + 3)^4

step-by-step explanation:

polynomials always have as many roots as their order. this is a 4th order polynomial- hence 4 roots!

complex roots of polynomials always come in pairs. the quadratic equation has the "+/-" in that will alwaysgenerate m+ni amd m-ni, so 7-2i must be a root of this polynomial equation.

the order of the numerator and denominator are both 2. so the horizontal asymptote is y=a2/b2 =7

verticle asymptotes are the forbidden x-values. f(x) becomes undefined at x=-3 because this value will cause a zero denominator.

a graph of r(x) will have vertical asymptotes at ±1 because these values will make the denominator zero. so the domain of the function cannot include ±1.

you 're wlecome! : )

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