Simplify 12x + 8x

News article reports that "Americans have differing views on two potentially inconvenient and invasive practices that airports c

OverLord2011 [107]

Answer:

1) p1=0.83

2) p2=0.81

3) Option B

4) p=0.82

5) s=0.03

6) z=0.67

7) P=0.50

8) Do not reject H0

Step-by-step explanation:

1) The proportion of Republicans who think the full-body scans should be applied in airports is equal to the ratio between the republicans that think it should over the total Republicans in the poll:

$p=X/n=258/311=0.83$

2) The proportion of Democrats who think the full-body scans should be applied in airports is equal to:

$p=X/n=294/363=0.81$

3) As we want to know if there is a difference in the proportions calculated, not if one is higher or lower than the other, the correct option is B:

$H_0:p_1-p_2=0\\\\H_a:p_1-p_2\neq0$

4) The pooled estimate of a proportion is the average of both proportions:

$\bar{p}=\frac{p_1+p_2}{2}= \frac{0.83+0.81}{2}=0.82$

5) The standard error can be calculated as:

$s=\sqrt{\frac{\bar{p}(1-\bar{p})}{n_1} +\frac{\bar{p}(1-\bar{p})}{n_2}} \\\\s=\sqrt{\frac{0.82*0.18}{311} +\frac{0.82*0.18}{363}} \\\\s=\sqrt{0.00047+0.00041} =\sqrt{0.00088}=0.03$

6) The z-statistic can be calculated as:

$z=\frac{p_1-p_2}{s}=\frac{0.83-0.81}{0.03}=\frac{0.02}{0.03}=0.67$

7) The P-value for z=0.67 is P=0.50 (from the standard normal distribution table).

$2P(Z>|z|)=0.50286$

8) If the significance level is 0.01, the P-value is bigger than the significance level. The effect is not significanct. The null hypothesis is not rejected.

There is not enough evidence to say that both proportions are different.

A. Do not reject H0

8 0

3 years ago

A random sample of 100 people from City A has an average IQ of 120 with a SD of 18. Independently of this, a random sample of 15

Sloan [31]

Answer:

$z=\frac{(120-116)-0}{\sqrt{\frac{18^2}{100}+\frac{15^2}{150}}}}=1.837$

$p_v =P(z>1.837)=1-P(Z$

Comparing the p value with a significance level for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that the average IQ on city A is signficantly higher than city B at 5% of singificance.

Step-by-step explanation:

$\bar X_{A}=120$ represent the mean for sample 1

$\bar X_{B}=116$ represent the mean for sample 2

$s_{A}=18$ represent the sample standard deviation for 1

$s_{B}=15$ represent the sample standard deviation for 2

$n_{A}=100$ sample size for the group 2

$n_{B}=150$ sample size for the group 2

$\alpha$ Significance level provided

z would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if residents of City A smarter on average, the system of hypothesis would be:

Null hypothesis: $\mu_{A}-\mu_{B}\leq 0$

Alternative hypothesis: $\mu_{A} - \mu_{B}> 0$

We don't have the population standard deviation's, but the sample sizes are large enough we can apply a z test to compare means, and the statistic is given by:

$z=\frac{(\bar X_{A}-\bar X_{B})-\Delta}{\sqrt{\frac{s^2_{A}}{n_{A}}+\frac{s^2_{B}}{n_{B}}}}$ (1)

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.

With the info given we can replace in formula (1) like this:

$z=\frac{(120-116)-0}{\sqrt{\frac{18^2}{100}+\frac{15^2}{150}}}}=1.837$

P value

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

$p_v =P(z>1.837)=1-P(Z$

Comparing the p value with a significance level for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that the average IQ on city A is signficantly higher than city B at 5% of singificance.

5 0

3 years ago

Do u want a link to ?

kumpel [21]

Answer:

I don't understand what this is

4 0

3 years ago

One more than three times a number is the same as the number decreased by 5 find the number

andre [41]

3x+1 = 5x-15

3x+1-5x = -15

-2x+1 = -15

-2x=-15-1

-2x=-16

x = 8

6 0

3 years ago

Read 2 more answers

In a pet adoption center specializing dogs and cats, the ratio of dogs to cats is 3:7. What percentage of the total number of an

DanielleElmas [232]

Answer:

30%

Step-by-step explanation:

7 0

4 years ago

Simplify 12x + 8x - 3x