Pls pls pls pls pls help

Question 13 I don’t know how to do it

Gekata [30.6K]

Answer:

y = - $\frac{1}{4}$ (x - 1)²(x + 2)(x + 6)

Step-by-step explanation:

The roots from the graph are

x = - 6 , then factor is (x + 6)

x = - 2 , then factor is (x + 2)

x = 1 ( multiplicity 2 ) , then factor is (x - 1)² then

y = a(x - 1)²(x + 2)(x + 6) ← a is a multiplier

To find a substitute any point on the graph into the equation

Using (0, - 3 ), then

- 3 = a(- 1)²(2)(6) = 12a ( divide both sides by 12 )

- $\frac{1}{4}$ = a

Then

y = - $\frac{1}{4}$ (x - 1)²(x + 2)(x + 6)

8 0

3 years ago

g A population is infected with a certain infectious disease. It is known that 95% of the population has not contracted the dise

trasher [3.6K]

Answer:

There is approximately 17% chance of a person not having a disease if he or she has tested positive.

Step-by-step explanation:

Denote the events as follows:

D = a person has contracted the disease.

+ = a person tests positive

- = a person tests negative

The information provided is:

$P(D^{c})=0.95\\P(+|D) = 0.98\\P(+|D^{c})=0.01$

Compute the missing probabilities as follows:

$P(D) = 1- P(D^{c})=1-0.95=0.05\\\\P(-|D)=1-P(+|D)=1-0.98=0.02\\\\P(-|D^{c})=1-P(+|D^{c})=1-0.01=0.99$

The Bayes' theorem states that the conditional probability of an event, say A provided that another event B has already occurred is:

$P(A|B)=\frac{P(B|A)P(A)}{P(B|A)P(A)+P(B|A^{c})P(A^{c})}$

Compute the probability that a random selected person does not have the infection if he or she has tested positive as follows:

$P(D^{c}|+)=\frac{P(+|D^{c})P(D^{c})}{P(+|D^{c})P(D^{c})+P(+|D)P(D)}$

$=\frac{(0.01\times 0.95)}{(0.01\times 0.95)+(0.98\times 0.05)}\\\\=\frac{0.0095}{0.0095+0.0475}\\\\=0.1666667\\\\\approx 0.1667$

So, there is approximately 17% chance of a person not having a disease if he or she has tested positive.

As the false negative rate of the test is 1%, this probability is not unusual considering the huge number of test done.

7 0

3 years ago

"A movie data base claims that the average length of movies is 117 minutes. A researcher collected a random sample of 160 movies

Sergeu [11.5K]

Answer:

We need to conduct a hypothesis in order to check if the mean the actual mean length of movies released during 2010-2015 is more than the data base value (a;ternative hypothesis) ,so then the system of hypothesis would be:

Null hypothesis: $\mu \leq 117$

Alternative hypothesis: $\mu > 117$

Step-by-step explanation:

Data given and notation

$\bar X=118.44$ represent the sample mean

$s=8.82$ represent the sample standard deviation

$n=160$ sample size

$\mu_o =117$ represent the value that we want to test

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

t 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 check if the mean the actual mean length of movies released during 2010-2015 is more than the data base value (a;ternative hypothesis) ,so then the system of hypothesis would be:

Null hypothesis: $\mu \leq 117$

Alternative hypothesis: $\mu > 117$

3 0

3 years ago

Question 2

Llana [10]

Hi here are the answers:)

Part A:

x = 3

Part B:

A = (3, 2)

Part C:

You can find the vertex by finding the mid-point of the focus and directrix. So the vertex is (-1, 2)

Part D:

The parabola opens left. This is because the parabola always opens toward the focus.

Part E:

The value of p is the distance from the focus to the vertex or the vertex to the directrix. To find p you can minus x-coordinate of focus with x-coordinate of the directrix, then divide it by 2. So this will be: -5-2/2 = -4

Part F:

p = -4

Part G:

$x=\frac{1}{4*-4}(y-2)^{2}-1$

Part H: image is attached down below. Fyi the C should be V (vertex)

Part I:

$x=\frac{1}{16} (y-2)^{2}-1$

*I'm not really sure about this one*

Part J:

1. x = 1/4 (y-3)>2+3

2. x = 1/12 (y +1)>2 +5

*I'm not really sure about this one either srry:(*

Hope this helped bai bye.

8 0

3 years ago

The floor of an elevator in a building is 30.33 feet above ground level. It then travels down to the lower level of the building

Ivan

The traveled distance is 40.819 feet (downward)

3 0

3 years ago