What is -5t+7=11t+25 solved

Jeff uses the expression 2(3b + 1) to determine how many books (b) he needs to order for his store. If b = 12, how many books sh

kari74 [83]

Answer:

73

Step-by-step explanation:

you write 12 instead of b

4 0

3 years ago

Read 2 more answers

If susan, janice, and melvin take 2.0 hours to walk to their school at a rate of 1.0 m/s, how far is their school from their hou

RideAnS [48]

Answer:

7.2 km

Step-by-step explanation:

Given that:

Hours taken = 2 hours

Walk rate = 1 m/s

Distance = Speed * time

Time taken in seconds = 2 * 60 * 60 = 7200 s

Hence,

Distance = 1 m/s * 7200s

Distance = 7200 meters

Distance in km = 7200 / 1000 = 7.2 km

3 0

2 years ago

A simple random sample of 100 observations was taken from a large population. The sample mean and the standard deviation were de

olga2289 [7]

Answer:

Se=1.2

Step-by-step explanation:

The standard error is the standard deviation of a sample population. "It measures the accuracy with which a sample represents a population".

The central limit theorem (CLT) states "that the distribution of sample means approximates a normal distribution, as the sample size becomes larger, assuming that all samples are identical in size, and regardless of the population distribution shape"

The sample mean is defined as:

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

And the distribution for the sample mean is given by:

$\bar X \sim N(\mu,\frac{\sigma}{\sqrt{n}})$

Let X denotes the random variable that measures the particular characteristic of interest. Let, X1, X2, …, Xn be the values of the random variable for the n units of the sample.

As the sample size is large,(>30) it can be assumed that the distribution is normal. The standard error of the sample mean X bar is given by:

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

If we replace the values given we have:

$Se=\frac{12}{\sqrt{100}}=1.2$

So then the distribution for the sample mean $\bar X$ is:

$\bar X \sim N(\mu=80,Se=1.2)$

5 0

2 years ago

A driveway has an area of 96 square feet. The width of the driveway is 8 feet.

Mrrafil [7]

Answer:

12 feet

Step-by-step explanation:

A driveway is rectangular in shape.

Therefore we can calculate the area using the formula;

$A = L \times W$

From the question;

The area,A=96 feet square

The width, W=8 feet

We substitute this values into the formula to find the length, L.

This implies that

$96 =L \times 8$

Dividing through by 8.

$\implies \frac{96}{8}= \frac{L \times 8}{8}$

$\implies L = 12$

Hence,the length of the driveway is 12 feet.

4 0

2 years ago

║║║║The length of a rectangle is 5 inches more than its width, x. The area of a rectangle can be represented by the equation x 2

lbvjy [14]

So given l = x+5 and w = x

area represented by equation x^2 +5x = 300

x^2 +5x -300 =0

(x+20)(x-15)=0

x+20 =0
x = -20

x-15=0
x=15

so from these result the width of rectangle equal 15 inches and the length of rectangle equal 20 inches

3 0

2 years ago