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1 year ago

6

The train station clock runs too fast and gains 7 minutes every 4 days. How many minutes and seconds will it have gained at the

of 10 days

1 answer:

dolphi86 [110]1 year ago

7 0

4 days 10 days Cross Multiplication
---------- = ------------
7 mins x

4x = 7*10
4x = 70
x = 70/4
x = 17.5

17.5 minutes = x

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What is an acrostic poem for the word percent

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1 year ago

In politics, marketing, etc. we often want to estimate a percentage or proportion p. One calculation in statistical polling is t

podryga [215]

Answer:

|0.254 ≤ p ≤ 0.286|

Step-by-step explanation:

Given that:

In a made up poll :

Proportion of people who like dark chocolate than milk chocolate (p) = 27%

Margin of Error = 1.6%

Hence,

p ± margin of error

27% ± 1.6%

(27 - 1.6)% ; (27 + 1.6)%

25.4% ; 28.6%

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Therefore ;

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Expressing p as an absolute value Inequality ;

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1 year ago

A probability calculator is required on this problem; answer to six decimal places. Suppose we will spin the wheel pictured 400

KiRa [710]

Answer:

$P(90< X< 110)= P(\frac{90-80}{8}$

And we can find this probability with this difference:

$P(90< X< 110)=P(z$

And we can find the real value with the following excel code using the binomial distribution:

"=BINOM.DIST(110,400,0.2,TRUE)-BINOM.DIST(89,400,0.2,TRUE)"

And we got 0.118 a very close value from the value obtained using the normal approximation

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:

$X \sim Binom(n=400, p=0.2)$

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:

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

We need to check the conditions in order to use the normal approximation.

$np=400*0.2=80 \geq 10$

$n(1-p)=400*(1-0.2)=320 \geq 10$

So we see that we satisfy the conditions and then we can apply the approximation.

If we appply the approximation the new mean and standard deviation are:

$E(X)=np=400*0.2=80$

$\sigma=\sqrt{np(1-p)}=\sqrt{400*0.2(1-0.2)}=8$

So then we can approximate the random variable as $X \sim N(\mu = 80, \sigma = 8)$

And we want this probability:

$P(90< X< 110)$

We can use the z score formula given by:

$z = \frac{x -\mu}{\sigma}$

And replacing we got:

$P(90< X< 110)= P(\frac{90-80}{8}$

And we can find this probability with this difference:

$P(90< X< 110)=P(z$

And we can find the real value with the following excel code using the binomial distribution:

"=BINOM.DIST(110,400,0.2,TRUE)-BINOM.DIST(89,400,0.2,TRUE)"

And we got 0.118 a very close value from the value obtained using the normal approximation

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1 year ago

At a track meet, the longest shot put throw by a boy is 25 feet and 8 inches. The longest shot put throw by a girl is 19 feet an

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2 years ago

Read 2 more answers

if f(x)= 2x^2+5sqrt(x-2), complete the following statement: The domain for f(x) is all real numbers _____ than or equal to 2. (f

SCORPION-xisa [38]

Answer:

Greater.

Step-by-step explanation:

The in the function $f(x)=2x^2+5\sqrt{x-2}$ , the square root term $\sqrt{x-2}$ has to give a real number if $f(x)$ is to be real. This can only happen if $x\geq 2$ because if $x$ then $\sqrt{x-2}$ will give a complex number and therefore $f(x)$ will not be real.

Thus, the domain for f(x) is all real numbers<em><u> greater</u></em><u> </u>than or equal to 2.

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