The tree in Kira’s backyard is 9 meters high. How high is it in centimeters?

What is 548.6814 rounded to the nearest thousandth

tankabanditka [31]

5 486 814 rounded to the nearest thousandth so here this is 6th digit:
because 7th digit is 4 we round down:
548.6814≈548,681

5 0

3 years ago

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A researcher claims that the mean of the salaries of elementary school teachers is greater than the mean of the salaries of seco

Brut [27]

Answer:

$t=\frac{(48250-45630)}{\sqrt{\frac{3900^2}{26}+\frac{5530^2}{24}}}}=1.921$

$df=n_{A}+n_{B}-2=26+24-2=48$

Since is a one sided test the p value would be:

$p_v =P(t_{(48)}>1.921)=0.0303$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can conclude that the mean for elementary school teachers is significantly higher than the mean for secondary teachers at 5% of significance

Step-by-step explanation:

Data given and notation

$\bar X_{A}=48250$ represent the mean of elementary teachers

$\bar X_{B}=45630$ represent the mean for secondary teachers

$s_{A}=3900$ represent the sample standard deviation for elementary teacher

$s_{B}=5530$ represent the sample standard deviation for secondary teachers

$n_{A}=26$ sample size selected

$n_{B}=24$ sample size selected

$\alpha=0.05$ 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 check if the mean of the salaries of elementary school teachers is greater than the mean of the salaries of secondary school teachers, the system of hypothesis would be:

Null hypothesis: $\mu_{A}-\mu_{B}\leq 0$

Alternative hypothesis: $\mu_{A}-\mu_{B}>0$

We don't know the population deviations, so for this case is better apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{A}-\bar X_{B})}{\sqrt{\frac{s^2_{A}}{n_{A}}+\frac{s^2_{B}}{n_{B}}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other".

Calculate the statistic

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

$t=\frac{(48250-45630)}{\sqrt{\frac{3900^2}{26}+\frac{5530^2}{24}}}}=1.921$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n_{A}+n_{B}-2=26+24-2=48$

Since is a one sided test the p value would be:

$p_v =P(t_{(48)}>1.921)=0.0303$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can conclude that the mean for elementary school teachers is significantly higher than the mean for secondary teachers at 5% of significance

5 0

2 years ago

5+3=4d please help me

ad-work [718]

So the object of this problem is to find out the value of d.

To do this, first think about 5 + 3. This equals 8, right? So the value of d times 4 has to equal 8.

No other number besides 2 would make sense. 2 would equal d because 4 x 2 is 8, and 5 + 3 is 8.

So you would write the answer as:

5+3=4(2)

4 0

3 years ago

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How do you do this problem 2/5+4a=-6/5 what does A = to?

a_sh-v [17]

Answer: A = -2/5

Step-by-step explanation:

- 6/5 - 2/5 = - 8/5 aka - 1 3/5

-1 3/5 ÷ 4 = - 2/5

4 0

3 years ago

In a cricket match, a batsman hits a boundary 6 times out of 30 balls he plays.Find the probability that he did not hit a bounda

Margarita [4]

Answer:

The probability of NOT hitting a boundary is (4/5).

Step-by-step explanation:

Let E: Be the event of hitting a boundary

now, Probability of any event E = $\frac{\textrm{Number of favorable outcomes}}{\textrm{Total number of outcomes}}$

Here, number of favorable outcomes = 6

So, P(E) = $\frac{6}{30} = \frac{1}{5}$

⇒Probability of hitting a six is 1/5

Now, P(E) + P(not E) = 1

So, P(not hitting a boundary ) = 1 - P(hitting a boundary)

= 1 - (1/5) = 4/5

Hence, the probability of NOT hitting a boundary is (4/5).

4 0

3 years ago