Can somebody help me ??

A manufacturer of sprinkler systems designed for fire protection claims that the average activating temperature is at least 135°

nirvana33 [79]

Answer:

$z=\frac{133-135}{\frac{3.3}{\sqrt{32}}}=-3.428$

$p_v =P(z$

If we compare the p value and the significance level given for example $\alpha=0.1$ we see that $p_v$ so we can conclude that we reject the null hypothesis, and the true mean is significantly lower than 135 so the claim not makes sense

Step-by-step explanation:

Data given and notation

$\bar X=133$ represent the sample mean

$\sigma=3.3$ represent the standard deviation for the population

$n=32$ sample size

$\mu_o =135$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to determine if the true mena is at least 135, the system of hypothesis would be:

Null hypothesis: $\mu \geq 135$

Alternative hypothesis: $\mu < 135$

We know the population deviation, so for this case is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{133-135}{\frac{3.3}{\sqrt{32}}}=-3.428$

Calculate the P-value

Since is a one-side lower test the p value would be:

$p_v =P(z$

Conclusion

If we compare the p value and the significance level given for example $\alpha=0.1$ we see that $p_v$ so we can conclude that we reject the null hypothesis, and the true mean is significantly lower than 135 so the claim not makes sense

3 0

2 years ago

About 3% of the population has a particular genetic mutation. 600 people are randomly selected.

Annette [7]

Answer:

Standard deviation for the number of people with the genetic mutation = 4.178

Step-by-step explanation:

Explanation:-

Given random sample size 'n' =600

proportion of the Population 'p'=3% or 0.03

Let 'X' be the random variable in binomial distribution

Mean of the binomial distribution

μ = n p

= 600 X 0.03

= 18

Mean of the binomial distribution ' μ ' =18

Standard deviation of the binomial distribution

σ = $\sqrt{npq} = \sqrt{600 X 0.03 X 0.97} = \sqrt{17.46} = 4.178$

Conclusion:-

Standard deviation for the number of people with the genetic mutation = 4.178

8 0

2 years ago

I need help with this now pls!!

zubka84 [21]

Answer:

first box 9.6 2nd box 7.2 third box 12

Step-by-step explanation:

9.6 is the missing height 12 is the hypotenuse is always last

6 0

2 years ago

1. Write 2 expressions that is equivalent to double (3x+4y)

jeyben [28]

i don't know sorry this is hard to do

8 0

2 years ago

Read 2 more answers

Find the polynomial of minimum degree, with real coefficients, zeros at

drek231 [11]

Answer:

$\huge\boxed{p(x)=4x^3-20x^2+4x+300}$

Step-by-step explanation:

$\text{If}\ x=4\pm3i\ \text{and}\ x=-3\ \text{are the zeros of a polynomial, then it has a form:}\\\\p(x)=\bigg(x-(4-3i)\bigg)\bigg(x-(4+3i)\bigg)\bigg(x-(-3)\bigg)\bigg(r(x)\bigg)\\\\p(x)=(x-4+3i)(x-4-3i)(x+3)\bigg(r(x)\bigg)\\\\p(x)=\underbrace{\bigg((x-4)+3i\bigg)\bigg((x-4)-3i\bigg)}_{\text{use}\ (a+b)(a-b)=a^2-b^2}(x+3)\bigg(r(x)\bigg)\\\\p(x)=\bigg((x-4)^2-(3i)^2\bigg)(x+3)\bigg(r(x)\bigg)\qquad\text{use}\ (a-b)^2=a^2-2ab+b^2$

$p(x)=(x^2-2(x)(4)+4^2-3^2i^2)(x+3)\bigg(r(x)\bigg)\qquad\text{use}\ i^2=-1\\\\p(x)=(x^2-8x+16-9(-1))(x+3)\bigg(r(x)\bigg)\\\\p(x)=(x^2-8x+16+9)(x+3)\bigg(r(x)\bigg)\\\\p(x)=(x^2-8x+25)(x+3)\bigg(r(x)\bigg)\qquad\text{use FOIL}:\ (a+b)(c+d)=ac+ad+bc+bd\\\\p(x)=\bigg((x^2)(x)+(x^2)(3)+(-8x)(x)+(-8x)(3)+(25)(x)+(25)(3)\bigg)\bigg(r(x)\bigg)\\\\p(x)=(x^3+3x^2-8x^2-24x+25x+75)\bigg(r(x)\bigg)\qquad\text{combine like terms}\\\\p(x)=(x^3-5x^2+x+75)\bigg(r(x)\bigg)$

$\text{The y-intercept is at 300}.\\\\\text{For}\ w(x)=a_nx^n+a_{n-1}x^{n-1}+a_{n-2}x^{n-2}+...+a_1x+a_0\\\\\text{y-intercept is}\ a_0\\\\\text{Therefore for}\ p(x)=(x^3-5x^2+x+75)\bigg(r(x)\bigg)\\\\\text{y-intercet is}\ 75\bigg(r(x)\bigg)\\\\75\bigg(r(x)\bigg)=300\qquad\text{divide both sides by 75}\\\\r(x)=4\\\\\text{Finally:}\\\\p(x)=(x^3-5x^2+x+75)(4)\qquad\text{use the distributive property}\\\\p(x)=(x^3)(4)+(-5x^2)(4)+(x)(4)+(75)(4)\\\\p(x)=4x^3-20x^2+4x+300$

7 0

3 years ago