All categories

3 years ago

Sue wants to use mental math to find 7 x 53. Write an expression she could use.

2 answers:

6 0

7 x 50 rounding the second digit to the nearest 10 and then multiply 7 x 3 and add the two answers together 350 + 21 = 371

pogonyaev3 years ago

3 0

Answer:

When we want solve expression mentally, that is, without writing down anything, a nice way is to separate number in simpler expressions, like tens for example.

So, in first place we could multiply 7 x 50, which involves a number expressed in tens, this product would be 350, then we multiply 7 x 3, which is 21, at the end, we sum both results 350 + 21 = 371. Therefore, the product is 371.

<h3>If we want to write an expression, it would be</h3>

7 x 50 + 7 x 3 = 350 + 21 = 371

You might be interested in

While her husband spent 2½ hours picking out new speakers, a statistician decided to determine whether the percent of men who en

AVprozaik [17]

Answer:

$z=\frac{p_{M}-p_{W}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{M}}+\frac{1}{n_{W}})}}$ (1)

$z=\frac{0.34848-0.34782}{\sqrt{0.34831(1-0.34831)(\frac{1}{66}+\frac{1}{23})}}=0.0057$

$p_v =P(Z>0.0057)=0.4977$

The p value is a very high value and using the significance level $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say the the percent of men who enjoy shopping for electronic equipment is NOT significantly higher than the percent of women who enjoy shopping for electronic equipment.

Step-by-step explanation:

1) Data given and notation

$X_{M}=23$ represent the number of men that said they enjoyed the activity of Saturday afternoon shopping

$X_{W}=8$ represent the number of women that said they enjoyed the activity of Saturday afternoon shopping

$n_{M}=66$ sample of male selected

$n_{W}=23$ sample of demale selected

$p_{M}=\frac{23}{66}=0.34848$ represent the proportion of men that said they enjoyed the activity of Saturday afternoon shopping

$p_{W}=\frac{8}{23}=0.34782$ represent the proportion of women with red/green color blindness

z would represent the statistic (variable of interest)

$p_v$ represent the value for the test (variable of interest)

2) Concepts and formulas to use

We need to conduct a hypothesis in order to check if the percent of men who enjoy shopping for electronic equipment is higher than the percent of women who enjoy shopping for electronic equipment , the system of hypothesis would be:

Null hypothesis: $p_{M} \leq p_{W}$

Alternative hypothesis: $p_{M} > p_{W}$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{M}-p_{W}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{M}}+\frac{1}{n_{W}})}}$ (1)

Where $\hat p=\frac{X_{M}+X_{W}}{n_{M}+n_{W}}=\frac{23+8}{66+23}=0.34831$

3) Calculate the statistic

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.34848-0.34782}{\sqrt{0.34831(1-0.34831)(\frac{1}{66}+\frac{1}{23})}}=0.0057$

4) Statistical decision

Using the significance level provided $\alpha=0.05$ , the next step would be calculate the p value for this test.

Since is a one side right tail test the p value would be:

$p_v =P(Z>0.0057)=0.4977$

So the p value is a very high value and using the significance level $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say the the percent of men who enjoy shopping for electronic equipment is NOT significantly higher than the percent of women who enjoy shopping for electronic equipment.

4 0

4 years ago

What is the inverse of f(x) = 2x+ 2?

HACTEHA [7]

Your inverse will be x = -1 .

4 0

4 years ago

Solve for 8x+c=k <br> Solve for X

ryzh [129]

Answer:

x=1

Step-by-step explanation: x will always be one unless the value of x is given for example, x wouldnt be one if in the question it says x=10 or x=9 or any number other than one

7 0

2 years ago

19. In the diagram below, which of the following pairs are vertical angles?

Brut [27]

Answer:

19 ) B (<2 and <5)

20) A(20)

21 and 22 Don't know sorry

4 0

2 years ago

A trapezoid has 9.2 inches base and 3.5 inches base, as well as 17 inches height. What is the area?

Tju [1.3M]

107.95 $in^{2}$

The area of a trapezoid is as follows:

A = $\frac{a + b}{2} h$

A and B are the lengths of the parallel lines of trapezoids. The parallel lines in this problem are 3.5 and 9.2. After adding those and dividing by 2, we multiply 17 to find the area of the trapezoid. (This is also shown in the attached picture)

4 0

4 years ago