In simplified form, V18 is

A school has 1,000 students on Wednesday, 300 students went on a field trip. What percent of students did not go on the field tr

iris [78.8K]

Answer:

%70

Step-by-step explanation:1,000=%100 300+%30 1000 - 300 = 700 so 700 + %70

7 0

2 years ago

Insurance companies are interested in knowing the population percent of drivers who always buckle up before riding in a car. Whe

kherson [118]

Answer:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$

$n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11$

And rounded up we have that n=1068

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Solution to the problem

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.03$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

We don't have a prior estimation for the proportion $\hat p$ so we can use 0.5 as an approximation for this case

And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11$

And rounded up we have that n=1068

5 0

2 years ago

Your water bill consists of five parts: A base hookup fee of $32.50, a water fee of $0.03 per gallon of water, a sewer fee of $0

Taya2010 [7]

hi

You have to keep calm and to treat data as it come.

1 ) Start by constant fees :

hook up fees is 32.50 and trash collection fees are 35

so contant fees : 32.50 +35 = 67.50

2 ) Now we have to deal with variable fees which depend on how much water is used

water fees :

0.03 per gallon, and we have 4 000 gallon, so :

0.03*4 000 = 120

Sewer fees :

0.01 per gallon, and we have 4 000 gallon, so :

0.01 * 4000 = 40

3 ) Total before taxation we have :

67.50 +120 +40 = 227.5

4) Now we apply tax on the total before tax.

tax is 5 % , which mean you rise the "off tax " price by 5 percent.

To grow a number of X % , you multiply by 1+ X/ 100

here X = 5 so the multiplicator is : 1 + 5/100 = 1.05

So total of the bill is : 227.5 * 1.05 = 238.875

The water compagny is probably going to round it up to 238.88

4 0

1 year ago

Which of the following is the correct value for x

USPshnik [31]

(1) 5 is the answer

7 0

3 years ago

Can I get some help please?

mamaluj [8]

Answer:

1) 68

/ \

4 17

/\

2 2

68=2*2*17

2) 104

/ \

4 26

/\ /\

2 2 2 13

104=2*2*2*13

3) 78

/\

2 39

/\

3 13

78=2*3*13

4) 225

/\

9 25

/\ /\

3 3 5 5

225=3*3*5*5

Second Part:

1) 45

/\

3 15

/\

3 5

45=3*3*5

2) 70

/\

2 35

/\

5 7

70=2*5*7

3) 54

/\

9 6

/\ /\

3 3 2 3

54=3*3*2*3

4) 126

/\

3 42

/\

3 14

/\

7 2

126=3*3*7*2

3 0

2 years ago