Evaluate the expression,<br> 32 +6*22-42=23

Doug had about $3,215 in savings while his brother had double that amount in savings. What is a reasonable amount that the broth

MaRussiya [10]

Answer: i think you would have to multiply

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

What’s the product of (-3)(-1)

Vlad1618 [11]

Answer:

-4

Step-by-step explanation:

negative plus a negative means add

You add the number then keep the negative sign

6 0

3 years ago

A manufacturer must test that his bolts are 4.00 cm long when they come off the assembly line. He must recalibrate his machines

storchak [24]

Answer:

The null hypothesis is $H_o: \mu = 4$ .

The alternate hypothesis is $H_a: \mu \neq 4$

The pvalue of the test is 0.0182 < 0.05, which means that there is sufficient evidence to show that the manufacturer needs to recalibrate the machines.

Step-by-step explanation:

A manufacturer must test that his bolts are 4.00 cm long when they come off the assembly line.

This means that the null hypothesis is that they are 4.00 cm long, that is:

$H_o: \mu = 4$

At the alternate hypothesis we test if it is different. So

$H_a: \mu \neq 4$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

4 is tested at the null hypothesis:

This means that $\mu = 4$

After sampling 196 randomly selected bolts off the assembly line, he calculates the sample mean to be 4.14 cm.

This means that $n = 196, X = 4.14$

He knows that the population standard deviation is 0.83 cm.

This means that $\sigma = 0.83$

Value of the test statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{4.14 - 4}{\frac{0.83}{\sqrt{196}}}$

$z = 2.36$

Pvalue of the test and decision:

The pvalue of the test is the probability that the sample mean is different by at least 4.14 - 4 = 0.14 from the target value, which is P(|z| > 2.36), which is 2 multiplied by the pvalue of z = -2.36.

Looking at the z-table, z = -2.36 has a pvalue of 0.0091

2*0.0091 = 0.0182

The pvalue of the test is 0.0182 < 0.05, which means that there is sufficient evidence to show that the manufacturer needs to recalibrate the machines.

5 0

2 years ago

What are the coordinates of the intersection of the graphs of 3x - y^2 = 12 and y = -3

inessss [21]

Answer:

(7,-3)

Step-by-step explanation:

y = -3

substitute in the first equation

3x - y^2 = 12

3x - (-3)^2 = 12

3x - 9 = 12

3x = 12 + 9

3x = 21

x = 7

coordinates of intersection (7,-3)

3 0

2 years ago

Ella collects 50 bottles to recycle. Of the bottles she collects, 19 are plastic and the rest are glass.

nekit [7.7K]

QUESTION A

The total number of bottles Ella collected is
$50$

The number of bottles that are plastic is

$19$

The percentage of bottles that are plastic is

$= \frac{number \: of \: plastic \: bottles}{total \: number \: of \: bottes} \times 100\%$

$= \frac{19}{50} \times 100\%$

$= 19 \times 2\%$
$= 38\%$

Therefore 38% of the bottles are plastic.

QUESTION B

The total number of bottles that are glass is
$50 - 19 = 31$

The total number of bottles Ella collected is
$50$

The percentage of bottles that is glass is
$= \frac{number \: of \: glass \: bottles}{total \: number \: of \: bottles} \times 100\%$

$= \frac{31}{50} \times 100\%$

$= 31 \times 2\%$
$= 62\%$

Therefore 62% of the bottles are glass

8 0

3 years ago

Evaluate the expression, 32 +6*22-42=23