Write the missing power of 10 in each equation.

You can answer only this question, it's ok:

Sophie [7]

1)100 or A
Angle = |30*H - (11/2)*M|, where H is the hours hand and M is the minutes hand

in this case: H = 4, M= 40
30*4 - (11/2)*40 = 120 - 220 = -100 = |-100| = 100
2)x=4y or C
If you plug in 0,0 you will get 0=4×0 or 0,0

7 0

4 years ago

A distance AB is observed repeatedly using the same equipment and procedures, and the results, in meters, are listed below: 67.4

skad [1K]

Answer:

a) $\bar X =\frac{67.401+67.400+67.402+67.396+67.406+67.401+67.396+67.401+67.405+67.404}{10}=67.401$

b) The sample deviation is calculated from the following formula:

$s=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

And for this case after replace the values and with the sample mean already calculated we got:

$s=0.0036$

If we assume that the data represent a population then the standard deviation would be given by:

$\sigma=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n}}$

And then the deviation would be:

$\sigma =0.00319$

Step-by-step explanation:

For this case we have the following dataset:

67.401, 67.400, 67.402, 67.396, 67.406, 67.401, 67.396, 67.401, 67.405, and 67.404

Part a: Determine the most probable value.

For this case the most probably value would be the sample mean given by this formula:

$\bar X =\frac{\sum_{i=1}^n X_i}{n}$

And if we replace we got:

$\bar X =\frac{67.401+67.400+67.402+67.396+67.406+67.401+67.396+67.401+67.405+67.404}{10}=67.401$

Part b: Determine the standard deviation

The sample deviation is calculated from the following formula:

$s=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

And for this case after replace the values and with the sample mean already calculated we got:

$s=0.0036$

If we assume that the data represent a population then the standard deviation would be given by:

$\sigma=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n}}$

And then the deviation would be:

$\sigma =0.00319$

3 0

4 years ago

Unfortunately, arsenic occurs naturally in some ground water†. A mean arsenic level of μ = 8.0 parts per billion (ppb) is consid

riadik2000 [5.3K]

Answer:

$t=\frac{7.2-8}{\frac{2.1}{\sqrt{41}}}=-2.439$

$p_v =P(t_{(40)}$

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the true mean is lower than 8 ppb at 1% of signficance. We need to be careful with this interpretation since the p value is near to the significance level.

Step-by-step explanation:

Data given and notation

$\bar X=7.2$ represent the mean height for the sample

$s=2.1/tex] represent the sample standard deviation [tex]n=41$ sample size

$\mu_o =8$ represent the value that we want to test

$\alpha=0.01$ 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 is less than 8, the system of hypothesis would be:

Null hypothesis: $\mu \geq 8$

Alternative hypothesis: $\mu < 8$

If we analyze the size for the sample is > 30 but 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".

Calculate the statistic

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

$t=\frac{7.2-8}{\frac{2.1}{\sqrt{41}}}=-2.439$

P-value

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

$df=n-1=41-1=40$

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

$p_v =P(t_{(40)}$

Conclusion

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the true mean is lower than 8 ppb at 1% of signficance. We need to be careful with this interpretation since the p value is near to the significance level.

4 0

4 years ago

Fine the value of x.

aliina [53]

Answer:

x = 20

Step-by-step explanation:

Hi there !

we have opposite angles =>

2 + 3x = 62

3x = 62 - 2

3x = 60

x = 60 : 3

x = 20

Good luck !

6 0

4 years ago

PWEASE help me (7th grade math work) will mark as a Brainliest and pls show work

pav-90 [236]

Answer:

Step-by-step explanation:

this week sold = $2,760

last week sold = $2,400

the difference from this week to last week = 2700-2400 = 360

that means it increased : 360 / 2400 = 0.15 (100%) = 15%

therefore, the increase of sale is 15%

6 0

3 years ago