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3 years ago

I am a 4 digit number all my digits are different they add up to 20 the hundred's digit is double than the one's digit

Mathematics

1 answer:

andrezito [222]3 years ago

7 0

Answer:

- 2864

Step-by-step explanation:

Given that,

The number is of 4 digits

All are different

The sum of the 4 digits = 20

Hundred's digit is twice than one's digit

A.T.Q.

Let the unit digit be 4. So, the hundred's digit would be 4 * 2 = 8

Now, we have

_8_4

We know that the sum of four digits is 20. Thus,

_ + 8 + _ + 4 = 20

∵ _ + _ = 20 - 12 = 8

The possible numbers must make a sum of 8. Thus, one possibility can be 2 and 6.

Therefore, the number can be

2864

( 2 + 8 + 6 + 4 = 20)

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To estimate the mean height μ of male students on your campus,you will measure an SRS of students. You know from government data

nexus9112 [7]

Answer:

a) $\sigma = 0.167$

b) We need a sample of at least 282 young men.

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by

$Z = \frac{X - \mu}{\sigma}$

This Zscore is how many standard deviations the value of the measure X is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

(a) What standard deviation must x have so that 99.7% of allsamples give an x within one-half inch of μ?

To solve this problem, we use the 68-95-99.7 rule. This rule states that:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviations of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we want 99.7% of all samples give X within one-half inch of $\mu$ . So $X - \mu = 0.5$ must have $Z = 3$ and $X - \mu = -0.5$ must have $Z = -3$ .

$Z = \frac{X - \mu}{\sigma}$

$3 = \frac{0.5}{\sigma}$

$3\sigma = 0.5$

$\sigma = \frac{0.5}{3}$

$\sigma = 0.167$

(b) How large an SRS do you need to reduce the standard deviationof x to the value you found in part (a)?

You know from government data that heights of young men are approximately Normal with standard deviation about 2.8 inches. This means that $\sigma = 2.8$

The standard deviation of a sample of n young man is given by the following formula

$s = \frac{\sigma}{\sqrt{n}}$

We want to have $s = 0.167$

$0.167 = \frac{2.8}{\sqrt{n}}$

$0.167\sqrt{n} = 2.8$

$\sqrt{n} = \frac{2.8}{0.167}$

$\sqrt{n} = 16.77$

$\sqrt{n}^{2} = 16.77^{2}$

$n = 281.23$

We need a sample of at least 282 young men.

6 0

4 years ago

Please help me!!!!!!!!!!!!!!!!!!!!

daser333 [38]

26.25 divided by 3 is 8.75 so the answer is B, just divide the about of money by the number of hours and you have your answer

6 0

2 years ago

A researcher wishes to conduct a study of the color preferences of new car buyers. Suppose that 50% of this population prefers t

Thepotemich [5.8K]

Answer:

The probability that exactly 12 buyers would prefer green

=0.00555

Step-by-step explanation:

We are given that

p=50%=50/100=0.50

n=14

We have to find the probability that exactly 12 buyers would prefer green.

q=1-p

q=1-0.50=0.50

Using binomial distribution formula

$P(X=x)=nC_r p^r q^{n-r}$

$P(x=12)=14C_{12}(0.50)^{12}(0.50)^{14-12}$

$P(x=12)=14C_{12}(0.50)^{12}(0.50)^2$

$P(x=12)=14C_{12}(0.50)^{14}$

$P(x=12)=\frac{14!}{12!2!}(0.50)^{14}$

$P(x=12)=\frac{14\times 13\times 12!}{12!2\times 1}(0.50)^{14}$

$P(x=12)=91\cdot (0.50)^{14}$

$P(x=12)=0.00555$

Hence, the probability that exactly 12 buyers would prefer green

=0.00555

3 0

3 years ago

The graph shows the solution to which system of inequalities?

Nimfa-mama [501]

Answer:

top right.

Step-by-step explanation:

5 0

3 years ago

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PLEASE HELP I GIVE BRAINLIEST

bearhunter [10]

Slope-intercept form is:

$\sf y=mx+b$

Where 'm' is the slope and 'b' is the y-intercept.

Only the first equation is in slope-intercept form, so that crosses out the first and last options. It also crosses out the second option since the first equation is already in slope-intercept form.

For the third option, let's convert the second equation into slope-intercept and see for ourselves:

$\sf 3y+x=-3$

Subtract 'x' to both sides:

$\sf 3y=-x-3$

Divide 3 to both sides:

$\sf y=-\dfrac{1}{3}x-1$

So option C is correct.

8 0

4 years ago

Read 2 more answers