Determine the product: (46.2 × 10–1) ⋅ (5.7 × 10–6). Write your answer in scientific notation.

Two of the steps in the derivation of the quadratic formula are shown below. Step 6: StartFraction b squared minus 4 a c Over 4

sergeinik [125]

Answer:

Step-by-step explanation:

From the step given step 6

(b² — 4ac) / 4a² = (x + b/2a)²

Mistake in question it is (x + b/2a)²

Step 7 given

±√(b² —4ac) /2a = x + b/2a

Mistake in question it is over 2a and not 1a.

1. The step taken from step 6 to step 7 is taking square roots of both sides

(b² — 4ac) / 4a² = (x + b/2a)²

Taking square of both sodes

√(b²—4ac) / √4a² = √(x + b/2a)²

√(b²—4ac) / 2a = x + b/2a

This is the required step 7.

Now, subtracting b/2a from both sides

√(b²—4ac) / 2a - b/2a= x + b/2a -b/2a

√(b²—4ac) / 2a — b/2a = x

(√(b²—4ac) — b)/2a = x

x = [—b ± √(b²—4ac)] / 2a

So, this is the required formula method

The discriminant is D = b²—4ac.

6 0

2 years ago

Read 2 more answers

The cost of 5 gallons of ice cream has a standard deviation of 8 dollars with a mean of 29 dollars during the summer. What is th

Feliz [49]

Answer:

97.74% probability that the sample mean would differ from the true mean by less than 1.9 dollars if a sample of 92 5-gallon pails is randomly selected

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central limit theorem:

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sample means with size n of at least 30 can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$

In this problem, we have that:

$\mu = 29, \sigma = 8, n = 92, s = \frac{8}{\sqrt{92}} = 0.8341$

What is the probability that the sample mean would differ from the true mean by less than 1.9 dollars if a sample of 92 5-gallon pails is randomly selected?

This is the pvalue of Z when X = 29 + 1.9 = 30.9 subtracted by the pvalue of Z when X = 29 - 1.9 = 27.1. So

X = 30.9

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{30.9 - 29}{0.8341}$

$Z = 2.28$

$Z = 2.28$ has a pvalue of 0.9887

X = 27.1

$Z = \frac{X - \mu}{s}$

$Z = \frac{27.1 - 29}{0.8341}$

$Z = -2.28$

$Z = -2.28$ has a pvalue of 0.0113

0.9887 - 0.0113 = 0.9774

97.74% probability that the sample mean would differ from the true mean by less than 1.9 dollars if a sample of 92 5-gallon pails is randomly selected

7 0

2 years ago

What do the symbols of mirrors and glass represent in this

luda_lava [24]

Question:

Read the excerpt from Julius Caesar, act 1, scene 2.

CASSIUS: ‘Tis just; And it is very much lamented, Brutus, That you have no such mirrors as will turn Your hidden worthiness into your eye, That you might see your shadow. I have heard 5 Where many of the best respect in Rome– Except immortal Caesar‐speaking of Brutus, And groaning underneath this age’s yoke, Have wished that noble Brutus had his eyes.

BRUTUS: Into what dangers would you lead me, Cassius, 10 That you would have me seek into myself For that which is not in me?

CASSIUS: Therefore, good Brutus, be prepared to hear. And since you know you cannot see yourself So well as by reflection, I, your glass, 15 Will modestly discover to yourself That of yourself which you yet know not of.

Answer:

The correct choice is D)

Explanation:

Cassius speaks of Brutus as one who is unable to see or know his own value and presumes to help him therewith. He does this by pointing out that many of the well respected people in Rome wish that he were in Caesars shoes as King.

Cheers!

7 0

2 years ago

An article estimates, with 90% confidence, that the proportion of elementary school teachers who are female is 82%. The article

GREYUIT [131]

Answer: (80% , 85%)

Step-by-step explanation:

We know that, confidence interval for population proportion is given by :-

(p-E , p+E)

, where p = sample proportion , E = Margin of error.

Given : Proportion of elementary school teachers who are female = 82%.

The article also states the maximum error of their estimate = 3%.

Then, the 90% confidence interval for the proportion of elementary school teachers who are female will be :

(82%-2% , 82%+3%)

= (80% , 85%)

Hence, the resulting 90% confidence interval for the proportion of elementary school teachers who are female = (80% , 85%)

5 0

2 years ago

Help with maths question please

mars1129 [50]

<h3>✽ - - - - - - - - - - - - - - - ~Hello There!~ - - - - - - - - - - - - - - - ✽</h3>

➷ Substitute -3 into g(x)

g(-3) = 2(-3) + 4

Solve:

g(x) = -2

Substitute this value into f(x)

f(-2) = 3(-2)^2

Solve:

f(-2) = 12

The answer is B. 12

➶ Hope This Helps You!

➶ Good Luck (:

➶ Have A Great Day ^-^

↬ ʜᴀɴɴᴀʜ ♡

6 0

2 years ago