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3 years ago

8

A ball is thrown from a height of 32 meters with an initial downward velocity of 2/ms. The ball's height h (in meters) after t s

econds is given by the following. =h−32−2t5t2 How long after the ball is thrown does it hit the ground?

1 answer:

Bumek [7]3 years ago

6 0

0=65-10t-5t^2

now what you want to do is multiply a and c

-5(t^2+2t-13)

Now just find the zeros

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Ben has a collection of 240 baseball cards. Of these cards, 30% once played

Luda [366]

Ok so lets start off with calculating the percentage. We have 240 cards so lets find 25% of them so lets use 240 times .25 we get 60 cards then take away 240 - 60 = 180. Next we do the 30% so 240 times .30 would be 72 so take away 180 from 72 thats 108. So there are 108 Houston Astros Cards.

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3 years ago

In a particular faculty 60% of students are men and 40% are women. In a random sample of 50 students what is the probability tha

zimovet [89]

Answer:

a) The expected value is given by:

$E(X) = np = 50*0.4 = 20$

and the variance is given by:

$Var(X) =np(1-p) = 50*0.4*(1-0.4) = 12$

b) $P(X>25)= 1-P(X\leq 25)$

And we can find this probability with the following Excel code:

=1-BINOM.DIST(25,50,0.4,TRUE)

And we got:

$P(X>25)= 1-P(X\leq 25)=0.0573$

c) 1) Random sample (assumed)

2) np= 50*0.4= 20 >10

n(1-p) =50*0.6= 30>10

3) Independence (assumed)

Since the 3 conditions are satisfied we can use the normal approximation:

$X \sim N(\mu = 20 , \sigma= 3.464)$

d) $P(X>25) = 1-P(Z< \frac{25-20}{3.464}) = 1-P(z$

e) $P(X>25)= P(X>25.5) = 1-P(X \leq 25.5)$

$P(X>25)= P(X>25.5) = 1-P(X \leq 25.5)= 1-P(Z$

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=50, p=0.4)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

Part a

The expected value is given by:

$E(X) = np = 50*0.4 = 20$

and the variance is given by:

$Var(X) =np(1-p) = 50*0.4*(1-0.4) = 12$

Part b

For this case we want to find this probability:

$P(X>25)= 1-P(X\leq 25)$

And we can find this probability with the following Excel code:

=1-BINOM.DIST(25,50,0.4,TRUE)

And we got:

$P(X>25)= 1-P(X\leq 25)=0.0573$

Part c

1) Random sample (assumed)

2) np= 50*0.4= 20 >10

n(1-p) =50*0.6= 30>10

3) Independence (assumed)

Since the 3 conditions are satisfied we can use the normal approximation:

$X \sim N(\mu = 20 , \sigma= 3.464)$

Part d

We want this probability:

$P(X>25) = 1-P(Z< \frac{25-20}{3.464}) = 1-P(z$

Part e

For this case we use the continuity correction and we have this:

$P(X>25)= P(X>25.5) = 1-P(X \leq 25.5)$

$P(X>25)= P(X>25.5) = 1-P(X \leq 25.5)= 1-P(Z$

4 0

3 years ago

The number of customers for a new online business can be modeled by y = 8x2 + 100x + 250, where x represents the number of month

kenny6666 [7]

The best prediction for the number of customers is 5450.

To find this value, you just need to plug in 20 for x into the expression. Then, evaluate it using the order of operations.

8(20)^2 + 100(20) + 250
8(400) + 100(20) + 250
3200 + 2000 + 250
5450

3 0

3 years ago

DUE AT 11:59 PLEASE HELP Only if you are good at geometry.

adoni [48]

Answer:

- reflection about the x-axis

- translation down 2 units

- translation right 3 units

Step-by-step explanation:

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3 years ago

A box contains 95 pink rubber bands and 90 brown rubber bands. You select a rubber band at random from the box. Find each probab

vivado [14]

Answer:A. The theoretical probability for pink is 95/185 or about 51.35%

B. The theoretical probability for brown is 90/185 or about 47.82%.

C. To find the experimental probability, we will make another fraction. The number of outcomes will be the numerator and the total will be the denominator.

Pink 36/69 = 52.17%

Brown 33/69 = 47.82%

Step-by-step explanation:

4 0

3 years ago