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3 years ago

Find the two-digit number which is 2 times the sum of its digits. Find a statement and number, please.

2 answers:

5 0

A two-digit number is twice the sum of its digit. If the tens digit is 7 less than the unit digit, find the number.
Let x= the unit digit
Then y= the tens digit
And 10y+x= the number

x+y= the sum of the digits
Now we are told that 10y+x=2(x+y) ------1st equation 
We are also told that y=x-7 ----------- 2nd Equation 
So our equations to solve are: 
(1) 10y+x=2(x+y)
(2) y=x-7


Hope it helps

dusya [7]3 years ago

4 0

Answer:

2(x + y) = 10x + y

the number is 18

i hop this helps!

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Three friends grow groups of sunflowers. Some think that Anna’s flowers are the tallest because the mean height of her flowers i

algol [13]

We have to find the graph where the mean of the flower heights is higher and the median is lower.

1st graph
M = ( 3 + 3 + 3 + 3 + 3 ) / 7
M = 15 / 7
Medium = 3
15 / 7 < 3 ( False )
2st graph
M = ( 2 + 6 + 2 + 1 + 1 + 3 ) / 6
M = 15 / 6
Medium = 4 / 2 = 2
15 / 6 > 2
So this is the requested chart.
Hope this helps, good studies.

7 0

2 years ago

Here’s another way to think about the number line model for 2 – (-3): if we were adding 2 + (-3), we’d first move two units to t

CaHeK987 [17]

Subtracting -9 from any number is the same as

A

subtracting 9 from that number.

7 0

3 years ago

Which graph shows the solution to the following inequality? 4d- 6 < 18 PLEASE HELP

kenny6666 [7]

Answer:

answer a

Step-by-step explanation:

$4d-6$ < $18$

Let's isolate $d$ on one side of the equation. Ignore the inequality for now. We'll deal with that later.

$4d-6=18\\4d-6+6=18+6\\4d=24\\\frac{4d}{4}=\frac{24}{4}\\ d=6$

Now, I'm going to bring back the inequality or < symbol. I only removed it when simplifying and isolating $d$ , but if this confuses you, just do your math and keep the inequality there.

$d$ < $6$

On a number line, this would include every number less than $6$ , due to the < (less than) symbol. This disqualifies answers b and d because they are showing every number greater than $6$ . But, how do we decide between answers a and c?
If a line has point at its beginning, $6$ , then that means that every number less than or equal to [ ≤ ] 6 is being shown, but our equation just says less than [ < ] 6, so answer a is our correct answer.

4 0

3 years ago

Read 2 more answers

Suppose a batch of metal shafts produced in a manufacturing company have a population standard deviation of 1.3 and a mean diame

lbvjy [14]

Answer:

54.86% probability that the mean diameter of the sample shafts would differ from the population mean by more than 0.1 inches

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are 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:

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

The Z-score measures how many standard deviations the measure 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.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this problem, we have that:

$\mu = 208, \sigma = 1.3, n = 60, s = \frac{1.3}{\sqrt{60}} = 0.1678$

What is the probability that the mean diameter of the sample shafts would differ from the population mean by more than 0.1 inches

Lesser than 208 - 0.1 = 207.9 or greater than 208 + 0.1 = 208.1. Since the normal distribution is symmetric, these probabilities are equal, so we find one of them and multiply by 2.

Lesser than 207.9.

pvalue of Z when X = 207.9. So

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

By the Central Limit Theorem

$Z = \frac{207.9 - 208}{0.1678}$

$Z = -0.6$

$Z = -0.6$ has a pvalue of 0.2743

2*0.2743 = 0.5486

54.86% probability that the mean diameter of the sample shafts would differ from the population mean by more than 0.1 inches

6 0

3 years ago

Find the first four terms of the sequence given by the following an=57-4(n-1),n=1,2,3

Crazy boy [7]

Answer:

57, 53, 49, 45

Step-by-step explanation:

Substitute for the n for n=1,2,3,4 so the first term is 57-4(1-1) so =57-4(0) so

a(1) = 57-0 = 57 so that is the 1st term

2nd term 57-4(2-1) so =57-4(1) so a(2) = 57-4 = 53, etc.

4 0

2 years ago