Can help me with this?

An athletics coach states that the distribution of player run times (in seconds) for a 100-meter dash is normally distributed wi

Elza [17]

Answer:

$P(X$

And we can find this probability using the normal standard distribution table and we got:

$P(z$

And the percentage faster than 13.28 seconds would be 91.9%

Step-by-step explanation:

Let X the random variable that represent the runtimes of a population, and for this case we know the distribution for X is given by:

$X \sim N(13,0.2)$

Where $\mu=13$ and $\sigma=0.2$

We want to find this probability:

$P(X$

And we can use the z score formula given by:

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

Using this formula we have:

$P(X$

And we can find this probability using the normal standard distribution table and we got:

$P(z$

And the percentage faster than 13.28 seconds would be 91.9%

8 0

3 years ago

What is the solution to the system of equation below Y equals -1/3 X +6 and X equals -6

Evgen [1.6K]

Answer:

y = 8

Step-by-step explanation:

y= $\frac{1}{3} x$ + 6

$x$ = -6

y=( $\frac{1}{3}$ x 6) + 6

y= 2+6 = 8

6 0

2 years ago

Polymer composite materials have gained popularity because they have high strength to weight ratios and are relatively easy and

Brums [2.3K]

Answer:

$t=\frac{51.6-48}{\frac{1.1}{\sqrt{10}}}=10.349$

$p_v =P(t_9>10.349)=1.34x10^{-6}$

If we compare the p value and the significance level given for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we reject the null hypothesis, and the the actual mean is significantly higher than 48 MPa at 5% of significance.

Step-by-step explanation:

1) Data given and notation

$\bar X=51.6$ represent the sample mean

$s=1.1$ represent the standard deviation for the sample

$n=10$ sample size

$\mu_o =48$ represent the value that we want to test

$\alpha=0.05$ 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 determine if the mean score is higher than 48, the system of hypothesis would be:

Null hypothesis: $\mu \geq 48$

Alternative hypothesis: $\mu > 48$

We don't know the population deviation, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (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".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{51.6-48}{\frac{1.1}{\sqrt{10}}}=10.349$

Calculate the P-value

First we find the degrees of freedom:

$df=n-1=10-1=9$

Since is a one-side upper test the p value would be:

$p_v =P(t_9>10.349)=1.34x10^{-6}$

Conclusion

If we compare the p value and the significance level given for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we reject the null hypothesis, and the the actual mean is significantly higher than 48 MPa at 5% of significance.

5 0

3 years ago

Question is in the image

Rudik [331]

The unit rate that the turtle is crawling is: (1/23)/(5/6) = (1/23)*(6/5) = 6/115 miles/hour.

4 0

2 years ago

Subtraction property of equality ur welcome x3

torisob [31]

Answer:

wut????????

Step-by-step explanation:

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6 0

2 years ago