Ask question

Ask question

All categories

2 years ago

9

Please answer Ill give 5 stars to right answers: a neighbors dog barked at tana the last 4 out of 5 times she walked by their ho

use
A: what is the experimental probability that the dog barks at tana when she walks past the house?
B: Predict the number of times the dog will bark at tana if she walks past the house 45 times

1 answer:

oksian1 [2.3K]2 years ago

6 0

Ratio of dog bark is 4:5

Multiply that by 20 each side

Ratio is now 80:100

So 80%

If they walk past 45 time you just have to multiply the ratio 4:5 by 9

36:45

So the dog would bark 36 times

You might be interested in

Shawna and her best friend Keisha go shopping. The function p(t) = 3x +2x-4x2+ 21 represents how much money each girl spent base

NNADVOKAT [17]

Answer:

$\$30$

Step-by-step explanation:

we have

$p(t)=3x+2x-4x^{2}+21$

<em>Find the amount of money that each girl spent</em>

For t= 2 hours

$p(2)=3(2)+2(2)-4(2)^{2}+21$

$p(2)=10-16+21$

$p(2)=\$15$

<em>Find the amount of money that they spend together</em>

Multiply by 2 the amount of money that each girl spent

$(2)\$15=\$30$

3 0

3 years ago

Multiple Choice

inessss [21]

Answer:
B
Step-by-step explication:
(1/4)/(3/8)=(2/3)

5 0

3 years ago

No link answers please!!

nignag [31]

Answer: X= 6 or X=-4

Step-by-step explanation:

$x^{2} -2x-24=0\\(x-6)(x+4)=0\\x-6=0 --> x=6\\x+4=---> x=-4$

8 0

3 years ago

Find the area of a plane figure bounded by lines

natulia [17]

Answer: 4.5

<u>Step-by-step explanation:</u>

First, find the points of intersection by solving the system.

y = x² + 2x + 4

y = x + 6

Solve by substitution:

x² + 2x + 4 = x + 6 ⇒ x² + x - 2 = 0 ⇒ (x + 2)(x - 1) = 0 ⇒ x = -2, x = 1

Now, integrate from x = -2 to x = 1

$\int\limits^1_2 {(x+6)-(x^{2}+2x+4) } \,$ <em>the bottom of the integral is -2 </em>

= $\int\limits^1_2 {x+6-x^{2}-2x-4 } \,$

= $\int\limits^1_2 {-x^{2}-x+2 } \,$

= $\frac{-x^{3}}{3} - \frac{x^{2}}{2}+2x\int\limits^1_2 {} \,$

= $(\frac{-1^{3}}{3} - \frac{1^{2}}{2}+2(1)) - (\frac{-(-2)^{3}}{3} - \frac{(-2)^{2}}{2}+2(-2))$

= $(\frac{-1}{3} - \frac{1}{2} +2) - (\frac{8}{3} -\frac{4}{2} -4)$

= $\frac{-9}{3} + \frac{3}{2} +6$

= -3 + 1.5 + 6

= 4.5

3 0

3 years ago

A laboratory scale is known to have a standard deviation (sigma) or 0.001 g in repeated weighings. Scale readings in repeated we

weqwewe [10]

Answer:

99% confidence interval for the given specimen is [3.4125 , 3.4155].

Step-by-step explanation:

We are given that a laboratory scale is known to have a standard deviation (sigma) or 0.001 g in repeated weighing. Scale readings in repeated weighing are Normally distributed with mean equal to the true weight of the specimen.

Three weighing of a specimen on this scale give 3.412, 3.416, and 3.414 g.

Firstly, the pivotal quantity for 99% confidence interval for the true mean specimen is given by;

P.Q. = $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean weighing of specimen = $\frac{3.412+3.416+3.414}{3}$ = 3.414 g

$\sigma$ = population standard deviation = 0.001 g

n = sample of specimen = 3

$\mu$ = population mean

<em>Here for constructing 99% confidence interval we have used z statistics because we know about population standard deviation (sigma).</em>

So, 99% confidence interval for the population mean, $\mu$ is ;

P(-2.5758 < N(0,1) < 2.5758) = 0.99 {As the critical value of z at 0.5% level

of significance are -2.5758 & 2.5758}

P(-2.5758 < $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ < 2.5758) = 0.99

P( $-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ < ${\bar X - \mu}$ < $2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.99

P( $\bar X-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.99

<u>99% confidence interval for</u> $\mu$ = [ $\bar X-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ , $\bar X+2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ]

= [ $3.414-2.5758 \times {\frac{0.001}{\sqrt{3} } }$ , $3.414+2.5758 \times {\frac{0.001}{\sqrt{3} } }$ ]

= [3.4125 , 3.4155]

Therefore, 99% confidence interval for this specimen is [3.4125 , 3.4155].

6 0

3 years ago