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3 years ago

Solve for b: (1/t)=(1/a)+(1/b)

Mathematics

1 answer:

crimeas [40]3 years ago

6 0

How to get answer by Mimiwhatsup:

Let's solve for b.

1/t = 1/a + 1/b

Step 1: Multiply both sides by t.

1= at+bt/ab

Step 2: Multiply both sides by ab.

ab=at+bt

Step 3: Add -bt to both sides.

ab+−bt=at+bt+−bt

ab−bt=at

Step 4: Factor out variable b.

b(a−t)=at

Step 5: Divide both sides by a-t.

b(a−t)/a−t = at/a−t

b= at/a−t

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A box contains eight cards numbered 2, 3, 4, 5, 6, 7, 8, 9. One card is selected at random and replaced. What is the probability

Archy [21]

Answer:

1/2

Step-by-step explanation:prime numbers ={2,3,5,7}

likelihood of prime numbers =number of prime numbers /all numbers

=4/8 , 4 divides itself once and 4 divides 8 twice.

=1/2

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3 years ago

In a study of the accuracy of fast food drive-through orders, McDonald’s had 33 orders that were not accurate among 362 orders o

melomori [17]

Answer:

A. We need to conduct a hypothesis in order to test the claim that the true proportion of inaccurate orders p is 0.1.

B. Null hypothesis: $p=0.1$

Alternative hypothesis: $p \neq 0.1$

C. $z=\frac{0.0912 -0.1}{\sqrt{\frac{0.1(1-0.1)}{362}}}=-0.558$

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

E. Fail to the reject the null hypothesis

F. 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 true proportion of inaccurate orders is not significantly different from 0.1.

Step-by-step explanation:

Data given and notation

n=362 represent the random sample taken

X=33 represent the number of orders not accurate

$\hat p=\frac{33}{363}=0.0912$ estimated proportion of orders not accurate

$p_o=0.10$ 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)

A: Write the claim as a mathematical statement involving the population proportion p

We need to conduct a hypothesis in order to test the claim that the true proportion of inaccurate orders p is 0.1.

B: State the null (H0) and alternative (H1) hypotheses

Null hypothesis: $p=0.1$

Alternative hypothesis: $p \neq 0.1$

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 $p_o$ .

C: Find the test statistic

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

$z=\frac{0.0912 -0.1}{\sqrt{\frac{0.1(1-0.1)}{362}}}=-0.558$

D: Find the critical value(s)

Since is a bilateral test we have two critical values. We need to look on the normal standard distribution a quantile that accumulates 0.025 of the area on each tail. And for this case we have:

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

P value

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 bilateral test the p value would be:

$p_v =2*P(z$

E: Would you Reject or Fail to Reject the null (H0) hypothesis.

Fail to the reject the null hypothesis

F: Write the conclusion of the test.

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 true proportion of inaccurate orders is not significantly different from 0.1.

6 0

3 years ago

Hi my sister is at school so I'm on her account

svlad2 [7]

Yo answer to yo question is d

5 0

3 years ago

A cafe offers senior citizens a 15% discount off its regular price of $8.95 for the dinner buffet.

jonny [76]

a) 75 percent of the regular price is the price for senior citizens.

b) $6.712 is the price for senior citizens.

<u>Step-by-step explanation</u>:

The regular price is the 100% = $8.95
The offer price for senior citizen = 15% discount from 100%

∴ Percent of the regular price for senior citizens = 100% - 15% = 75%

The price for the senior citizens = 75% of $8.95

⇒ (75/100) $\times$ 8.95

⇒ 0.75 $\times$ 8.95

⇒ 6.712 dollars.

∴ The price for senior citizens = $6.712

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3 years ago

Distributive property -8(1+5m)

Stolb23 [73]

Answer:

im pretty sure that it is -48 there is a chance im wrong

Step-by-step explanation:

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3 years ago