Write an equivalent expression for 27x+18

A certain pen has been designed so that true average writing lifetime under controlled conditions (involving the use of a writin

Morgarella [4.7K]

Answer:

(a) We reject our null hypothesis.

(b) We fail to reject our null hypothesis.

(c) We fail to reject our null hypothesis.

Step-by-step explanation:

We are given that a certain pen has been designed so that true average writing lifetime under controlled conditions (involving the use of a writing machine) is at least 10 hr.

A random sample of 18 pens is selected.

<u><em>Let </em></u> $\mu$ <u><em> = true average writing lifetime under controlled conditions</em></u>

So, Null Hypothesis, $H_0$ : $\mu \geq$ 10 hr {means that the true average writing lifetime under controlled conditions is at least 10 hr}

Alternate Hypothesis, $H_A$ : $\mu$ < 10 hr {means that the true average writing lifetime under controlled conditions is less than 10 hr}

<u>The test statistics that is used here is one-sample t test statistics;</u>

T.S. = $\frac{\bar X -\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean

s = sample standard deviation

n = sample size of pens = 18

n - 1 = degree of freedom = 18 -1 = 17

<u>Now, the decision rule based on the critical value of t is given by;</u>

If the value of test statistics is more than the critical value of t at 17 degree of freedom for left-tailed test, then <u>we will not reject our null hypothesis</u> as it will not fall in the rejection region.

If the value of test statistics is less than the critical value of t at 17 degree of freedom for left-tailed test, then <u>we will reject our null hypothesis</u> as it will fall in the rejection region.

(a) Here, test statistics, t = -2.4 and level of significance is 0.05.

<em>Now, at 0.05 significance level, the t table gives critical value of -1.74 at 17 degree of freedom.</em>

Here, clearly the value of test statistics is less than the critical value of t as -2.4 < -1.74, so we reject our null hypothesis.

(b) Here, test statistics, t = -1.83 and level of significance is 0.01.

<em>Now, at 0.051 significance level, the t table gives critical value of -2.567 at 17 degree of freedom.</em>

Here, clearly the value of test statistics is more than the critical value of t as -2.567 < -1.83, so we fail to reject our null hypothesis.

(c) Here, test statistics, t = 0.57 and level of significance is not given so we assume it to be 0.05.

<em>Now, at 0.05 significance level, the t table gives critical value of -1.74 at 17 degree of freedom.</em>

Here, clearly the value of test statistics is more than the critical value of t as -1.74 < 0.57, so we fail to reject our null hypothesis.

8 0

3 years ago

Please do them step by step;

ELEN [110]

For the first one c-9=(2)(4)+6
You are gonna multiply 2 and 4 first, 2*4=8. Now you have c-9=8+6. 8+6=14. So now the equation is c-9=14. Now we are going to add 9 to both sides. So c=23
For the second equation 10+y=90. We are going to subtract 10 from both sides. So, y=80.
Third, add 4 to both sides. a=10.
Fourth, subtract 8 from both sides. d=-9
Fifth, 5+2(3+4)=-x.
First we are going to add 3 and 4. 3+4=7. 5+2(7)=-x. Next we are going to multiply 2 and 7. 2*7=14. 5+14=-x. 5+14=19. So our equation is 19=-x. Next we are going to multiply both sides by -1. Making our final equation x=-19.
c=23
y=80
a=10
d=-9
x=-19
I hope that helps, if you need any further explanation just ask.<span />

3 0

3 years ago

PLEASE HELP ME !! ILL MARK U BRAINIEST

madreJ [45]

Answer:

<h2>My name: CORN CORNELIUS CORNWALL</h2><h2>My Age: 209374329 years old</h2><h2>Fav song : Baby by justin bieber</h2><h2>most legendary thing My name: CORN CORNELIUS CORNWALL</h2><h2>My Age: 209374329 years old</h2><h2>Fav song : Baby by justin bieber</h2><h2>most legendary thing that i got : clbsdbdbfdbub penguin membershipMy name: CORN CORNELIUS CORNWALL</h2><h2>My Age: 209374329 years old</h2><h2>Fav song : Baby by justin bieber</h2><h2>most legendary thing that i got : club penguin membershipthat i got : club penguin membership</h2>

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

A documentary is a film that

DanielleElmas [232]

Answer:

1. the answer is nonfictional story about a person, topic, or event

Step-by-step explanation:

hope this helps

3 0

2 years ago