Help needed please extra points given

A die is rolled 30 timeswhat is the probability of getting x even number

Mama L [17]

Probability of getting an even number (2,4,6) out of (1,2,3,4,5,6) =3/6=1/2

The probability of getting x even number :
(using the binomial probability)

30Cx (1/2)^x . (1/2)^(30-x)

6 0

4 years ago

Bob is reading a 445 page book. He has already read 157 pages. If he reads 24 pages a day, how long will it take him to finish t

Sever21 [200]

Answer:

12 days

Step-by-step explanation:

Set up an equation with y = mx + b, where m is the rate and b is the y-intercept (starting value)

Let x represent how many days it takes and y represent how many pages he read:

445 = 24x + 157

Solve for x:

288 = 24x

12 = x

So, it will take him 12 days to finish the book

3 0

3 years ago

Read 2 more answers

The perimeter of a rectangle is 53 inches. The length of the rectangle is 5 less than twice it’s width. Solve the system using 2

djverab [1.8K]

Answer:

length of rectangle=16 inches

width of rectangle=10.5 inches

Step-by-step explanation:

given ,perimeter of rectangle=53 inches

let ,length of rectangle= l=2b-5

width of rectangle=b

p=2(l+b)

53=2(2b-5+b)

26.5=3b-5

31.5=3b

b= $\frac{31.5}{3}$

b=10.5 inches

l=21-5=16 inches

5 0

3 years ago

A new bridge structure requires triangles that are in a ratio of 1:1. If AC = 2x + 10 and EC = 4x − 18, find the distance betwee

gavmur [86]

Answer: The required distance between the top and bottom of the bridge is 76 feet.

Step-by-step explanation: Given that a new bridge structure requires triangles that are in a ratio of 1:1.

AC = 2x + 10 and EC = 4x − 18.

We are to find the distance between the top and bottom of the bridge, in feet.

Since the two triangles ACB and DCE are in the ratio 1 : 1, so their corresponding sides are also in the ratio 1 : 1.

The sides AC and EC are corresponding to each other, so we must have

$AC:EC=1:1\\\\\Rightarrow \dfrac{AC}{EC}=\dfrac{1}{1}\\\\\Rightarrow AC=EC\\\\\Rightarrow 2x+10=4x-18\\\\\Rightarrow 4x-2x=10+18\\\\\Rightarrow 2x=28\\\\\Rightarrow x=\dfrac{28}{2}\\\\\Rightarrow x=14.$

Therefore, the distance between the top and bottom of the bridge is

$EA\\\\=EC+AC\\\\=4x-18+2x+10\\\\=6x-8=6\times14-8\\\\=84-8\\\\=76~\textup{feet}.$

Thus, the required distance between the top and bottom of the bridge is 76 feet.

6 0

4 years ago

Fairfield Homes is developing two parcels near Pigeon Fork, Tennessee. In order to test different advertising approaches, it use

evablogger [386]

Answer:

(1) Null Hypothesis, $H_0$ : $\mu_1 = \mu_2$

Alternate Hypothesis, $H_1$ : $\mu_1\neq \mu_2$

(2) Test statistics = -1.48

(3) At the 0.05 significance level, Fair field conclude that the population means are same.

Step-by-step explanation:

Let $\mu_1$ = mean annual family income for 12 people making inquiries at the first development

$\mu_2$ = mean annual family income for 24 people making inquiries at the second development

$s_1$ = standard deviation of annual family income for 12 people making inquiries at the first development

$s_2$ = standard deviation of annual family income for 24 people making inquiries at the second development

$n_1$ = sample of people of first development i.e. 12

$n_2$ = sample of people of second development i.e. 24

(1) Null Hypothesis, $H_0$ : $\mu_1 = \mu_2$ {population means are same}

Alternate Hypothesis, $H_1$ : $\mu_1\neq \mu_2$ {population means are different}

<u>DECISION RULE ;</u>

If the test statistics is less than the critical value of t from table at 5% significance level, then we will accept null hypothesis, $H_0$ .
If the test statistics is more than the critical value of t from table at 5% significance level, then we will reject null hypothesis, $H_0$ .

(2) The test statistics is given by;

$\frac{(X_1bar -X_2bar) - (\mu_1-\mu_2)}{s_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ ~ $t_n__1+n_2-2$

where, $X_1bar$ = Sample mean income of people at first development

= $153,000

$X_2bar$ = Sample mean income of people at second development = $171,000

$s_1$ = $42,000 and $s_2$ = $30,000

$s_p= \sqrt{\frac{(n_1-1)s_1^{2}+(n_2-1)s_2^{2} }{n_1+n_2-2}}$ = $\sqrt{\frac{(12-1)42000^{2}+(24-1)30000^{2} }{12+24-2}}$ = 34344.30

Test statistics = $\frac{(153000 -171000) - 0}{34344.30\sqrt{\frac{1}{12}+\frac{1}{24} } }$ ~ $t_3_4$

= -1.48

(3) At 5% level of significance, t table gives critical value of 2.032 at 34 degree of freedom.Since our test statistics is less than the critical value of t so considering our decision rule, we will accept null hypothesis.

And conclude that population means are same.

4 0

4 years ago