HELP!!!

I am offering 35 points. We are doing a project on scale drawings and scale factors. We have to make a scale drawing of a skyscr

stepan [7]

your answer is in decimals so your answer is rounded to 1.8 inches tall

3 0

4 years ago

A random sample of 500 adult residents of Maricopa County found that 356 were in favor of increasing the highway speed limit to

zzz [600]

Answer:

$z=1.04$

$p_v =2*P(Z>1.04)\approx 0.298$

Comparing the p value with the significance level given $\alpha=0.05$ 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't say that the proportion of people in favor of the increased speed limit not differs significantly between the two groups.

Step-by-step explanation:

1) Data given and notation

$X_{PC}=297$ represent the number of residents of Pima County in favor of the increased speed limit

$X_{MC}=356$ represent the number of residents of Maricopa County in favor of the increased speed limit

$n_{PC}=400$ sample of Pima County selected

$n_{MC}=500$ sample of Maricopa County selected

$p_{PC}=\frac{297}{400}=0.743$ represent the proportion of residents of Pima County in favor of the increased speed limit

$p_{MC}=\frac{356}{500}=0.712$ represent the proportion of residents of Maricopa County in favor of the increased speed limit

z would represent the statistic (variable of interest)

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

$\alpha=0.05$ significance level given

2) Concepts and formulas to use

We need to conduct a hypothesis in order to check if is there is a difference in the support for in increasing the speed limit between the residents of the two counties, the system of hypothesis would be:

Null hypothesis: $p_{PC} - p_{MC}=0$

Alternative hypothesis: $p_{PC} - \mu_{MC} \neq 0$

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

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

Where $\hat p=\frac{X_{PC}+X_{MC}}{n_{PC}+n_{MC}}=\frac{297+356}{400+500}=0.726$

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

3) Calculate the statistic

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

$z=\frac{0.743-0.712}{\sqrt{0.726(1-0.726)(\frac{1}{400}+\frac{1}{500})}}=1.04$

4) Statistical decision

Since is a two side test the p value would be:

$p_v =2*P(Z>1.04)\approx 0.298$

Comparing the p value with the significance level given $\alpha=0.05$ 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't say that the proportion of people in favor of the increased speed limit not differs significantly between the two groups.

8 0

3 years ago

one particular ice cream parlor has 28 different flavors available. How many ice cream cups are possible if you order 4 scoops?

Lena [83]

Answer:

20,475 cream cups are possible.

Step-by-step explanation:

The order in which the flavors are chosen is not important, which means that the combinations formula is used to solve this question.

Combinations formula:

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

In this question:

4 cups from a set of 28.

So

$C_{28,4} = \frac{28!}{4!24!} = 20475$

20,475 cream cups are possible.

7 0

3 years ago

Why is the formula for finding the area of a parallelogram for the same as for the rectangle?

bagirrra123 [75]

Answer:

Step-by-step explanation:

The reasons why the area of parallelogram and rectangle are the is that the two opposite sides are equal, they have the lines of symmetry, the sum of their angles is equal to 360°

5 0

3 years ago

Please help me I need this to be answered right I now

Sergeeva-Olga [200]

I am only in fifth grade so i really don't know!!!!!! sorry to say this i really want to help you!!!!!!!! I sure need help here!!!!! i have been bullied by everyone at school and i have a crush!!!!!!!!!!!!!!!!!!!!!! can i get some advice to like talk to him!? Whenever he's around i get nervous and i don't even get a chance to say what i want him to know!!!!!!!!!!!! please help me

5 0

4 years ago