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Explain why 0.25x0.4 has only one decimal place in the product.

Irina-Kira [14]

Answer:

0.1 is the answer of that equation but 0.1 can also be written as 0.100 or 0.10000 or and amount of zero just when you have zeros in the decimal places you usally dont count them so 0.100 is the same as 0.1 the same would also call for somthing like 0.40000 it can be written as 0.4 instead.

7 0

3 years ago

2x^3+2x^2-19x+20=0 find the roots of the polynomial equation

Alenkinab [10]

The answer is x=-4, (3<span>±i)/2</span>

5 0

3 years ago

Clara has 9 pounds of apples. She needs 1 1/4 pounds to make one apple pie. If she saves 2 pounds for applesauce, how many pies

sattari [20]

Answer:

She can make 6 pies.

8 0

3 years ago

Read 2 more answers

Researchers are interested in the effect of a certain nutrient on the growth rate of plant seeding. Use a hydroponics grow proce

Rashid [163]

Answer:

The 95% confidence interval for the mean would be given by (56.604;68.596)

The 99% confidence interval for the mean would be given by (53.196;72.004)

Step-by-step explanation:

1) Previous concepts

When we compute a confidence interval for the mean, we are interested on the parameter population mean, and we use the info from the sample to estimate this parameter.

2) Basic operations

The sample mean can be calculated with the following formula

$\sum_{i=1}^n \frac{x_i}{n}$

Using excel we can use this function to calculate the mean:

=AVERAGE(54.2,59.8,61.8,63.3,65.1,71.4)

The value obtained is $\bar X=62.6$

In order to find the sample deviation we can use this formula

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

And using excel we can use this function to calculate the sample standard deviation:

=STDEV.S(54.2,59.8,61.8,63.3,65.1,71.4)

The value obtained is $s=5.713$

The sample size for this case is n=6, n<30 so then is better use the t distribution to calculate the margin of error. First we need to calculate the degrees of freedom, on this case $df=n-1=6-1=5$

The formula for the confidence interval would be given by:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

3) Part a

If we want a 95% or 0.95 of confidence, then the value for the signficance is $\alpha=1-0.95=0.05$ , and $\alpha/2=0.025$ , and $1-\frac{\alpha}{2}=0.975$ so we can find the critical t value with the following formula in excel:

=T.INV(0.975,5)

And we got $t_{\alpha/2}= 2.571$

And we can replace into equation (1) and we got:

$62.6 \pm 2.571\frac{5.713}{\sqrt{6}}$

And using excel with the following formulas we got:

=62.6-2.571*(5.713/SQRT(6)) = 56.604

=62.6+2.571*(5.713/SQRT(6)) = 68.596

So the 95% confidence interval for the mean would be given by (56.604;68.596)

4) Part b

If we want a 99% or 0.99 of confidence, then the value for the signficance is $\alpha=1-0.99=0.01$ , and $\alpha/2=0.005$ , and $1-\frac{\alpha}{2}=0.995$ so we can find the critical t value with the following formula in excel:

=T.INV(0.995,5)

And we got $t_{\alpha/2}= 4.032$

And we can replace into equation (1) and we got:

$62.6 \pm 4.032\frac{5.713}{\sqrt{6}}$

And using excel with the following formulas we got:

=62.6-4.032*(5.713/SQRT(6)) = 53.196

=62.6+4.032*(5.713/SQRT(6)) = 72.004

So the 99% confidence interval for the mean would be given by (53.196;72.004)

8 0

3 years ago

The sum of two positive integers, a and b, is at least 30. The difference of the two integers is at least 10. If b is the greate

KIM [24]

a + b ≥ 30, b ≥ a + 10, the system of inequalities could represent the values of a and b

option A

<u>Step-by-step explanation:</u>

Here we have , The sum of two positive integers, a and b, is at least 30. The difference of the two integers is at least 10. If b is the greater integer, We need to find which system of inequalities could represent the values of a and b . Let's find out:

Let two numbers be a and b where b>a . Now ,