4.5x + 1.25=12.5 what is x?

Ksivusya [100]

4 fractions that are equal to 1/3

1*2/3*2 = 2/6

2/6

1*3/1*3 = 3/9

3/9

1*4/3*4 = 4/12

4/12

1*5/3*5 = 5/15

5/15

5 0

3 years ago

The basic measure of mass in the metric system is called

tigry1 [53]

Answer:

Grams.

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Elijah has $0.55 worth of pennies and nickels. He has twice as many nickels as pennies. Determine the number of pennies and the

maxonik [38]

Answer:

The number of nickels are 10 and number of pennies are 5.

Step-by-step explanation:

Given:

Elijah has $0.55 worth of pennies and nickels.

He has twice as many nickels as pennies.

Now, to determine the number of pennies and the number of nickels that Elijah has.

Let the number of nickels be $x.$

And the number of pennies be $y.$

As given that he has twice as many nickels as pennies.

$2y=x$

$x=2y.$ ......(1)

The total worth of worth of pennies and nickels = $0.55.

As, the value of a penny = $0.01.

And the value of a nickel = $0.05.

Now, to get the number of pennies and the number of nickels that Elijah has:

$0.05(x)+0.01(y)=0.55$

Putting the value of $x$ from equation (1):

$0.05(2y)+0.01(y)=0.55$

$0.10y+0.01y=0.55$

$0.11y=0.55$

Dividing both sides by 0.11 we get:

$y=5.$

The number of pennies = 5.

Now, putting the value of $y$ in equation ( 1 ) we get:

$x=2y\\x=2\times 5\\x=10.$

The number of nickels = 10.

Therefore, the number of nickels are 10 and number of pennies are 5.

3 0

4 years ago

Which statements are true

Lemur [1.5K]

Answer:

A

Step-by-step explanation:

A is the answer A is the answer

5 0

3 years ago

In order to ensure efficient usage of a server, it is necessary to estimate the mean number

juin [17]

Answer:

a. [36.19;39.21]

b. Reject the null hypothesis. The population mean of users that are connected at the same time is greater than 35.

Step-by-step explanation:

Hello!

Your study variable is,

X: "number of users of one server at a time"

The objective is to estimate the mean, for this, a sample of n=100 times was taken and the standard deviation S= 9.2 and the sample mean is X[bar]= 37.7 were calculated.

You need to study the population mean, for this you need your variable to have at least normal distribution. Since you don't have information about its distribution, but the sample is big enough (n≥30) you can apply the Central Limit Theorem and approximate the distribution of the sample mean X[bar] to normal:

X[bar]≈N(μ;σ²/n)

a. With this approximation, you can construct the 90% Confidence Interval using the approximate Z

[X[bar] ± $Z_{1-\alpha /2}$ * S/√n]

$Z_{1-\alpha /2}$ = $Z_{0.95}$ = 1.64

[37.7± 1.64* 9.2/√100]

[36.19;39.21]

b. You need to test if the population mean is greater than 35 with a level of significance of 1%.

The hypothesis is:

H₀: μ ≤ 35

H₁: μ > 35

α: 0.01

This is a one-tailed test so you have only one critical level (right tail):

$Z_{1\alpha } = Z_{0.99} = 2.33$

This means that if the value of the calculated statistic is equal or greater than 2.33 you will reject the null Hypothesis.

If the value is less than 2.33 you will support the null hypothesis.

The statistic is:

Z= X[bar] - μ = 37.7 - 35 = 2.93

S/√n 9.2/10

The value 2.93 > 2.33, so you reject the null hypothesis. This means that the population mean of users that are connected at the same time is greater than 35.

Note: To make the decision using the interval calculated on a), the hypothesis should have been two-tailed and the confidence and significance levels complementary.

I hope it helps!

7 0

3 years ago