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3 years ago

What is the simplified expression for -2a^2b+a^2-5ab+3ab^2-b^2+2(a^2b+2ab)

Mathematics

1 answer:

WINSTONCH [101]3 years ago

7 0

Answer:

Step-by-step explanation:

Hello,

$-2a^2b+a^2-5ab+3ab^2-b^2+2(a^2b+2ab)\\\\=-2a^2b+a^2-5ab+3ab^2-b^2+2a^2b+4ab\\\\=a^2+3ab^2-ab-b^2$

Thanks

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Answer:

90% confidence interval for the percent of the population who consider the death penalty to be "fair" is [54.4% , 61.6%].

Step-by-step explanation:

We are given that in October 2010, Gallup Poll asked 510 randomly sampled adults the question, "Generally speaking, do you believe the death penalty is applied fairly or unfairly in this country today?"

Of these, 58% answered "fairly", 36% said "unfairly" and 7% said they didn't know.

Firstly, the Pivotal quantity for 90% confidence interval for the population proportion is given by;

P.Q. = $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ~ N(0,1)

where, $\hat p$ = sample proportion who answered death penalty "fair" = 58%

n = sample of adults = 510

p = population percentage

Here for constructing 90% confidence interval we have used One-sample z test for proportions.

So, 90% confidence interval for the population percentage, p is ;

P(-1.645 < N(0,1) < 1.645) = 0.90 {As the critical value of z at 5% level

of significance are -1.645 & 1.645}

P(-1.645 < $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < 1.645) = 0.90

P( $-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < $\hat p-p$ < $1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ) = 0.90

P( $\hat p-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < p < $\hat p+1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ) = 0.90

90% confidence interval for p = [ $\hat p-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ , $\hat p+1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ]

= [ $0.58-1.645 \times {\sqrt{\frac{0.58(1-0.58)}{510} } }$ , $0.58+1.645 \times {\sqrt{\frac{0.58(1-0.58)}{510} } }$ ]

= [0.544 , 0.616]

Therefore, 90% confidence interval for the percent of the population who consider the death penalty to be "fair" is [54.4% , 61.6%].

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3 years ago

The ages of commercial aircraft are normally distributed with a mean of 13.5 years and a standard deviation of 7.3 years. what p

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3 years ago

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Answer:

x≥ -7 x -y/3

Step-by-step explanation:

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3 years ago

A 64-foot tall monument casts a shadow 16 feet long. If Kyle is stsnding nearby and is 6'3 tall, find the length of his shadow.

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Answer: Length of his shadow is 18 feet.

Step-by-step explanation:

Since we have given that

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So, we need to find the length of its shadow.

So, according to question, we get that

$\dfrac{64\times 12}{16\times 12}=\dfrac{72}{x}\\\\4=\dfrac{72}{x}\\\\4x=72\\\\x=\dfrac{72}{4}\\\\x=18\ feet$

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3 years ago

What is the simplified expression for -2a^2b+a^2-5ab+3ab^2-b^2+2(a^2b+2ab)​

What is the simplified expression for -2a^2b+a^2-5ab+3ab^2-b^2+2(a^2b+2ab)