A submarine that is 245 feet below sea level descends 83 feet and then ascends

In ΔQRS, q = 1.3 inches, r = 1.6 inches and ∠S=157°. Find the length of s, to the nearest 10th of an inch.

hjlf

Answer:

2.8

Step-by-step explanation:

using cosine rule

$s^{2}$ = $1.3^{2} + 1.6^{2} - 2(1.3)(1.6)cos 157$

s = $\sqrt{8.0793}$ = 2.842 = 2.8

8 0

3 years ago

Which quadratic equation is equivalent to (x+2)2+5(x+2)-6=0

professor190 [17]

$(x+2)^2+5(x+2)-6=0\\\\x^2+2\cdot x\cdot2+2^2+5\cdot x+5\cdot2-6=0\\\\x^2+4x+4+5x+4-6=0\\\\x^2+9x+2=0$

6 0

3 years ago

4.One attorney claims that more than 25% of all the lawyers in Boston advertise for their business. A sample of 200 lawyers in B

AleksAgata [21]

Answer:

$z=\frac{0.315 -0.25}{\sqrt{\frac{0.25(1-0.25)}{200}}}=2.123$

$p_v =P(Z>2.123)=0.0169$

The p value obtained was a very low value and using the significance level given $\alpha=0.05$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of lawyers had used some form of advertising for their business is significantly higher than 0.25 or 25% .

Step-by-step explanation:

1) Data given and notation

n=200 represent the random sample taken

X=63 represent the lawyers had used some form of advertising for their business

$\hat p=\frac{63}{200}=0.315$ estimated proportion of lawyers had used some form of advertising for their business

$p_o=0.25$ is the value that we want to test

$\alpha=0.05$ represent the significance level

Confidence=95% or 0.95

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

2) Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that more than 25% of all the lawyers in Boston advertise for their business:

Null hypothesis: $p\leq 0.25$

Alternative hypothesis: $p > 0.25$

When we conduct a proportion test we need to use the z statistic, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

3) Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.315 -0.25}{\sqrt{\frac{0.25(1-0.25)}{200}}}=2.123$

4) Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

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

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

$p_v =P(Z>2.123)=0.0169$

The p value obtained was a very low value and using the significance level given $\alpha=0.05$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of lawyers had used some form of advertising for their business is significantly higher than 0.25 or 25% .

8 0

3 years ago

How many minutes in a year

tresset_1 [31]

There are 525600 minutes in a regular year

There are 527040 minutes in a leap year

I hope that's help !

6 0

3 years ago

Which one of the following pairs of angles x and y are supplementary, answer ASAP i NEED help please, 10 points per person

vampirchik [111]

Answer:3. B 4. B

Step-by-step explanation:3. Supplementary equals 180, 113 + 67 = 180

4 0

3 years ago