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2 years ago

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A set of middle school student heights are normally distributed with a mean of 150 centimeters and a standard deviation of20 cen

timeters. Let X= the height of a randomly selected student from this set. Find P(X>175) is greater than, 175, right parenthesis.

1 answer:

Tanzania [10]2 years ago

8 0

Answer:

can you post a picture of the question plz

Step-by-step explanation:

need a pic

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The number of letters in Stephanie's full name is sixteen less than twice the number of letters in Amy's full name. If the numbe

Anestetic [448]

Answer:

19 letters

Step-by-step explanation:

Suppose Number of Amy's full name letters = X

Number of Stephanie's full name letters = Y

Now, according to given condition that ''number of letters in Stephanie's full name is sixteen less than twice the number of letters in Amy's full name'',

Equation 1 becomes

Y = 2X-16

Now, according to second condition, product of their names' letter is 418. So,

Equation 2 becomes

XY = 418

Deducing value of X from equation 1,

X = (Y+16)/2

Putting this value in equation 2 we get,

{(Y+16)/2}*Y = 418,

By simplifying this equation we get a quadritic equation

(Y^2)+16Y-836=0

By breaking middle term (You can use quadratic formula here as well)

(Y^2)+38Y-22Y-836=0

Y(Y+38)-22(Y+38)=0

(Y-22)(Y+38)=0

At this stage we have two values for Y,

Y=22, or Y=-38

Now considering only positive value since the number of letters in a name can not be in negative number,

Y=22,

So X=(Y+16)/2

X=19

7 0

3 years ago

Each day, Robin commutes to work by bike with probability 0.4 and by walking with probability 0.6. When biking to work injuries

kvasek [131]

Answer:

64.65% probability of at least one injury commuting to work in the next 20 years

Step-by-step explanation:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

$P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}
$

In which

x is the number of sucesses

e = 2.71828 is the Euler number

$\mu$ is the mean in the given interval.

Each day:

Bikes to work with probability 0.4.

If he bikes to work, 0.1 injuries per year.

Walks to work with probability 0.6.

If he walks to work, 0.02 injuries per year.

20 years.

So

$\mu = 20*(0.4*0.1 + 0.6*0.02) = 1.04$

Either he suffers no injuries, or he suffer at least one injury. The sum of the probabilities of these events is decimal 1. So

$P(X = 0) + P(X \geq 1) = 1$

We want $P(X \geq 1)$ . Then

$P(X \geq 1) = 1 - P(X = 0)$

In which

$P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}
$

$P(X = 0) = \frac{e^{-1.04}*1.04^{0}}{(0)!} = 0.3535
$

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.3535 = 0.6465$

64.65% probability of at least one injury commuting to work in the next 20 years

3 0

3 years ago

Need help please it’s due today show work

Diano4ka-milaya [45]

Answer:

D

Step-by-step explanation:

6 0

3 years ago

A coffee company wants to make sure that their coffee is being served at the right temperature. If it is too hot, the customers

Cerrena [4.2K]

Answer:

Null hypothesis: $\mu = 65$

Alternative hypothesis: $\mu \neq 65$

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

For this case the value of $\mu$ represent the parameter associated to the population (True average of cofee temperature)

Step-by-step explanation:

Data given and notation

$\bar X=70.2$ represent the mean height for the sample

$s$ represent the sample standard deviation for the sample

$n=20$ sample size

$\mu_o =765$ 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 true mean i equal to 70.2, the system of hypothesis would be:

Null hypothesis: $\mu = 65$

Alternative hypothesis: $\mu \neq 65$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

For this case the value of $\mu$ represent the parameter associated to the population (True average of cofee temperature)

3 0

3 years ago

Bananas are curved because they grow towards the sun ☀️

VLD [36.1K]

Hope you have a good day

5 0

2 years ago

Read 2 more answers