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4 years ago

Three multiplied by the sum of 4 and a number is the same as 18 more than the number. Find the number.

1 answer:

6 0

3(4+n)=18+n
distribute
12+3n=18+n
minus n both sides
12+2n=18
minus 12 both sides
2n=6
divide by 2
n=3

the number is 3
equation is
3(4+n)=18+n

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If if the branding division were to experience the same percentage increase from year 2 to year 3 as they did from year 1 to yea

Sedaia [141]

Since the basis is from year 1 to year 2, calculate first for the difference of their percentages. That would be:

Difference = year 2 - year 1
Difference = 2.32% - 1.1% = 1.22%

We apply this same value of percentage increase from year 2 to year. Thus, the percentage for year 3 is:

% Year 3 = % Year 2 + percentage increase
% Year 3 = 2.32% + 1.22%
% Year 3 = 3.54%

6 0

3 years ago

Solve the equation<br>2/3 h - 1/3 h + 11 = 8<br><br>h = ?

Deffense [45]

Answer:

$2 \div 3h - 1 \div 3 h+ 11 = 8 \\ 2 - 1 \div 3h = - 3 \\ 1 \div 3h = - 3 \\ - 9h = 1 \\ h = - 1 \div 9$

-1/9 is the answer

8 0

3 years ago

Solve the following system of equations by elimination

olya-2409 [2.1K]

Answer:

y = -6

x = 1

Step-by-step explanation:

-x + 2y = -13

-x - 2y = 11

Sum the equations:

-x -x = -2x

+2y - 2y = 0

-13 + 11 = -2

then

-2x = -2

x = -2/-2

x = 1

from the first eq.

-x + 2y = -13

-1 + 2y = -13

2y = -13 + 1

2y = -12

y = -12/2

y = -6

check:

from the second eq.

-x -2y = 11

-1 -(2*-6) = 11

-1 -(-12) = 11

-1 + 12 = 11

5 0

2 years ago

A survey collected data on annual credit card charges in seven different categories of expenditures: transportation, groceries,

Andru [333]

Answer:

A. Null and alternative hypothesis:

$H_0: \mu_d=0\\\\H_a:\mu_d\neq 0$

B. Yes. At a significance level of 0.05, there is enough evidence to support the claim that there is signficant difference between the population mean credit card charges for groceries and the population mean credit card charges for dining out.

P-value = 0.00002

C. As the difference is calculated as (population 1 − population 2), being population 1: groceries and population 2: dinning out, and knowing there is evidence that the true mean difference is positive, we can say that the groceries annual credit card charge is higher than dinning out annual credit card charge.

The point estimate is the sample mean difference d=$840.

The 95% confidence interval for the mean difference between the population means is (490, 1190).

Step-by-step explanation:

This is a hypothesis test for the population mean.

The claim is that there is signficant difference between the population mean credit card charges for groceries and the population mean credit card charges for dining out.

Then, the null and alternative hypothesis are:

$H_0: \mu_d=0\\\\H_a:\mu_d\neq 0$

The significance level is 0.05.

The sample has a size n=42.

The sample mean is M=840.

As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=1123.

The estimated standard error of the mean is computed using the formula:

$s_M=\dfrac{s}{\sqrt{n}}=\dfrac{1123}{\sqrt{42}}=173.2827$

Then, we can calculate the t-statistic as:

$t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{840-0}{173.2827}=\dfrac{840}{173.2827}=4.848$

The degrees of freedom for this sample size are:

$df=n-1=42-1=41$

This test is a two-tailed test, with 41 degrees of freedom and t=4.848, so the P-value for this test is calculated as (using a t-table):

$\text{P-value}=2\cdot P(t>4.848)=0.00002$

As the P-value (0.00002) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

At a significance level of 0.05, there is enough evidence to support the claim that there is signficant difference between the population mean credit card charges for groceries and the population mean credit card charges for dining out.

We have to calculate a 95% confidence interval for the mean difference.

The t-value for a 95% confidence interval and 41 degrees of freedom is t=2.02.

The margin of error (MOE) can be calculated as:

$MOE=t\cdot s_M=2.02 \cdot 173.283=350$

Then, the lower and upper bounds of the confidence interval are:

$LL=M-t \cdot s_M = 840-350=490\\\\UL=M+t \cdot s_M = 840+350=1190$

The 95% confidence interval for the mean difference is (490, 1190).

7 0

3 years ago

Please, help me. I'm not sure what to do.

Nezavi [6.7K]

Answer is d, its simple....

3 0

4 years ago