Ask question

Ask question

All categories

3 years ago

7

Solve 3x²-x-2=0. Please show all work.

1 answer:

lorasvet [3.4K]3 years ago

3 0

3x²-x-2=0

Δ=1+24=25 (Δ=b²-4ac)

x₁,₂= $\frac{1(+/-)\sqrt{25} }{6}$

x₁,₂= $\frac{1(+/-)5}{6}$

x1= $\frac{1+5}{6}$ =6/6=1

x2= $\frac{1-5}{6}$ = $\frac{-2}{3}$

so

x1=1

x2= $\frac{-2}{3}$

You might be interested in

Which is the best estimate for the quotient of 198.32 ÷ 9.001?

Whitepunk [10]

I would believe it to be 22

4 0

3 years ago

Read 2 more answers

#3 The sales tax on a $20 shirt was 9%.

d1i1m1o1n [39]

Answer:

$1.80

Step-by-step explanation:

20 x 0.09 = 1.8

8 0

2 years ago

What is the answer to 93+(68+7)

Rasek [7]

93+(68+7)do whats in the parenthesis first

93(75)

multiply them together

6975 is your answer plz rate my answer as brainliest

7 0

3 years ago

Simplify the expression where possible. (x 2) 5

zysi [14]

The answer is going to be 10x

7 0

3 years ago

Read 2 more answers

Standard Error from a Formula and a Bootstrap Distribution Sample A has a count of 30 successes with and Sample B has a count of

tia_tia [17]

Answer:

Using a formula, the standard error is: 0.052

Using bootstrap, the standard error is: 0.050

Comparison:

The calculated standard error using the formula is greater than the standard error using bootstrap

Step-by-step explanation:

Given

Sample A Sample B

$x_A = 30$ $x_B = 50$

$n_A = 100$ $n_B =250$

Solving (a): Standard error using formula

First, calculate the proportion of A

$p_A = \frac{x_A}{n_A}$

$p_A = \frac{30}{100}$

$p_A = 0.30$

The proportion of B

$p_B = \frac{x_B}{n_B}$

$p_B = \frac{50}{250}$

$p_B = 0.20$

The standard error is:

$SE_{p_A-p_B} = \sqrt{\frac{p_A * (1 - p_A)}{n_A} + \frac{p_A * (1 - p_B)}{n_B}}$

$SE_{p_A-p_B} = \sqrt{\frac{0.30 * (1 - 0.30)}{100} + \frac{0.20* (1 - 0.20)}{250}}$

$SE_{p_A-p_B} = \sqrt{\frac{0.30 * 0.70}{100} + \frac{0.20* 0.80}{250}}$

$SE_{p_A-p_B} = \sqrt{\frac{0.21}{100} + \frac{0.16}{250}}$

$SE_{p_A-p_B} = \sqrt{0.0021+ 0.00064}$

$SE_{p_A-p_B} = \sqrt{0.00274}$

$SE_{p_A-p_B} = 0.052$

Solving (a): Standard error using bootstrapping.

Following the below steps.

Open Statkey
Under Randomization Hypothesis Tests, select Test for Difference in Proportions
Click on Edit data, enter the appropriate data
Click on ok to generate samples
Click on Generate 1000 samples ---- <em>see attachment for the generated data</em>

From the randomization sample, we have:

Sample A Sample B

$x_A = 23$ $x_B = 57$

$n_A = 100$ $n_B =250$

$p_A = 0.230$ $p_A = 0.228$

So, we have:

$SE_{p_A-p_B} = \sqrt{\frac{p_A * (1 - p_A)}{n_A} + \frac{p_A * (1 - p_B)}{n_B}}$

$SE_{p_A-p_B} = \sqrt{\frac{0.23 * (1 - 0.23)}{100} + \frac{0.228* (1 - 0.228)}{250}}$

$SE_{p_A-p_B} = \sqrt{\frac{0.1771}{100} + \frac{0.176016}{250}}$

$SE_{p_A-p_B} = \sqrt{0.001771 + 0.000704064}$

$SE_{p_A-p_B} = \sqrt{0.002475064}$

$SE_{p_A-p_B} = 0.050$

5 0

3 years ago