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REY [17]
3 years ago
14

Joe borrowed $35 on Monday, then he borrowed $55 on Tuesday. On Friday he paid back $20. How much does Joe still owe?

Mathematics
1 answer:
Zinaida [17]3 years ago
3 0

Answer:

$70

Step-by-step explanation:

35 + 55 = 90

90 - 20 = 70

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A manufacturer of a new medication on the market for Alzheimer's disease makes a claim that the medication is effective in 65% o
NeX [460]

Answer:

z=\frac{0.639 -0.65}{\sqrt{\frac{0.65(1-0.65)}{180}}}=-0.309  

p_v =P(z  

So the p value obtained was a very high value and using the significance level given \alpha=0.05 we have p_v>\alpha so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the proportion of adults with the medication was effective is not significantly less than 0.65

Step-by-step explanation:

Data given and notation

n=180 represent the random sample taken

X=115 represent the adults with the medication was effective

\hat p=\frac{115}{180}=0.639 estimated proportion of adults with the medication was effective

p_o=0.65 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)  

Concepts and formulas to use  

We need to conduct a hypothesis in order to test the claim that true proportion is less than 0.65.:  

Null hypothesis:p \geq 0.65  

Alternative hypothesis:p < 0.65  

When we conduct a proportion test we need to use the z statisitc, 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.

Calculate the statistic  

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

z=\frac{0.639 -0.65}{\sqrt{\frac{0.65(1-0.65)}{180}}}=-0.309  

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 left tailed test the p value would be:  

p_v =P(z  

So the p value obtained was a very high value and using the significance level given \alpha=0.05 we have p_v>\alpha so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the proportion of adults with the medication was effective is not significantly less than 0.65

3 0
3 years ago
8 ( j - 4 ) = 2(4j - 16 )
Tanya [424]
8j-32=8j-32
J=j
Js value is infinite
7 0
3 years ago
Read 2 more answers
The ratio of the radii of two circles is 2:3. The diameter of the smaller circle is 15 mm. What is the length of the diameter of
mixer [17]
The answer is 11.25 mm.

A diameter of a circle is twice of its radius: d = 2r    ⇒ r = d/2

small circle                                       large circle
radius: r1                                           radius: r2 = ?
diameter: d1 = 15 mm
⇒ r1 = d1/2 = 15/2 mm

Since t<span>he ratio of the radii of two circles is 2:3, we have:
r1 : r2 = 2 : 3
which can also be expressed as:
</span>\frac{r1}{r2}= \frac{2}{3}
<span>
We know that r1 is 7.5, so let's implement it:
</span>\frac{7.5}{r2} = \frac{2}{3}

Let's multiply both sides of the by 3r2:
3r2* \frac{7.5}{r2} =3r2* \frac{2}{3}
⇒ 3 * 7.5 = 2*r2
     22.5 = 2*r2
⇒ r2= \frac{22.5}{2} =11.25 mm

5 0
3 years ago
Read 2 more answers
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Liula [17]
If you want to solve that put it in the formula to find the slope
M=
Y1-y2
---------
X1-x2

And plug that into slope int form with one of the points to find the y int/ b value and then your have ur equ
4 0
3 years ago
While conducting experiments, a marine biologist selects water depths from a uniformly distributed collection that vary between
aleksandr82 [10.1K]

Answer:

The probability that a randomly selected depth is between 2.25 m and 5.00 m is 0.55.

Step-by-step explanation:

Let the random variable <em>X</em> denote the water depths.

As the variable water depths is continuous variable, the random variable <em>X</em> follows a continuous Uniform distribution with parameters <em>a</em> = 2.00 m and <em>b</em> = 7.00 m.

The probability density function of <em>X</em> is:

f_{X}(x)=\frac{1}{b-a};\ a

Compute the probability that a randomly selected depth is between 2.25 m and 5.00 m as follows:

P(2.25

                               =\frac{1}{5.00}\int\limits^{5.00}_{2.25} {1} \, dx\\\\=0.20\times [x]^{5.00}_{2.25} \\\\=0.20\times (5.00-2.25)\\\\=0.55

Thus, the probability that a randomly selected depth is between 2.25 m and 5.00 m is 0.55.

6 0
3 years ago
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