IS THIS CORRECT ?? HELP ASAP THANKS!

Sedaia [141]

Answer:

Step-by-step explanation:

Rounding means making a number simpler but keeping its value close to what it was. The result is less accurate, but easier to use. Example: 73 rounded to the nearest ten is 70, because 73 is closer to 70 than to 80. But 76 goes up to 80. There are many ways to round.

5 0

2 years ago

Read 2 more answers

Solve the equation. x2 + 8x − 9 = 0 A) x = 1 B) x = 9 C) x = 9 or x = −1 D) x = −9 or x = 1

yarga [219]

Answer:D. X= -9 or x= 1

X2 + 8x - 9 = 0

7 0

3 years ago

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g A certain financial services company uses surveys of adults age 18 and older to determine if personal financial fitness is cha

leva [86]

Answer:

Null hypothesis: $p_{1} = p_{2}$

Alternative hypothesis: $p_{1} \neq p_{2}$

$z=\frac{0.410-0.35}{\sqrt{0.385(1-0.385)(\frac{1}{1000}+\frac{1}{700})}}=2.502$

$p_v =2*P(Z>2.502)= 0.0123$

Comparing the p value with the significance level assumed $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to to reject the null hypothesis, and we can say that the proportion analyzed is significantly different between the two groups at 5% of significance.

Step-by-step explanation:

Data given and notation

$X_{1}=410$ represent the number of people indicating that their financial security was more than fair for the recent year

$X_{2}=245$ represent the number of people indicating that their financial security was more than fair for the year before

$n_{1}=1000$ sample 1 selected

$n_{2}=700$ sample 2 selected

$p_{1}=\frac{410}{1000}=0.410$ represent the proportion estimated of indicating that their financial security was more than fair this year

$p_{2}=\frac{245}{700}=0.35$ represent the proportion estimated of indicating that their financial security was more than fair the year before

$\hat p$ represent the pooled estimate of p

z would represent the statistic (variable of interest)

$p_v$ represent the value for the test (variable of interest)

$\alpha$ significance level given

Concepts and formulas to use

We need to conduct a hypothesis in order to check if is there is a difference between the two proportions, the system of hypothesis would be:

Null hypothesis: $p_{1} = p_{2}$

Alternative hypothesis: $p_{1} \neq p_{2}$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{410+245}{1000+700}=0.385$

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Calculate the statistic

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.410-0.35}{\sqrt{0.385(1-0.385)(\frac{1}{1000}+\frac{1}{700})}}=2.502$

Statistical decision

Since is a two sided test the p value would be:

$p_v =2*P(Z>2.502)= 0.0123$

Comparing the p value with the significance level assumed $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to to reject the null hypothesis, and we can say that the proportion analyzed is significantly different between the two groups at 5% of significance.

7 0

3 years ago

Please help asap! Correct answers only!

ozzi

Answer:

$98100

Step-by-step explanation:

Using the given formula :

I = P × R × T

I = 90000 × 3/100 × 3

I = $8100

He saves = 8100 + 90000 = $98100

6 0

2 years ago

There are many regulations for catching lobsters off the coast of New England including required permits, allowable gear, and si

Georgia [21]

Answer:

Probability that the sample mean carapace length is more than 4.25 inches = 0.9993

Step-by-step explanation:

Given - There are many regulations for catching lobsters off the coast

of New England including required permits, allowable gear, and

size prohibitions. The Massachusetts Division of Marine Fisheries

requires a minimum carapace length measured from a rear eye

socket to the center line of the body shell. For a particular local

municipality, any lobster measuring less than 3.37 inches must

be returned to the ocean. The mean carapace length of the

lobsters is 4.01 inches with a standard deviation of 2.13 inches.

A random sample of 60 lobsters is obtained.

To find - What is the probability that the sample mean carapace length

is more than 4.25 inches?

Proof -

Given that, μ = 4.01, σ = 2.13 , n = 60

Now,

μₓ⁻ = σ / √n

= $\frac{2.13}{\sqrt{60} }$

= $\frac{2.13}{7.746}$ = 0.275

⇒μₓ⁻ = 0.275

Now,

P(X⁻ > 3.37) = 1 - P( X⁻ < 3.37)

= 1 - P(z < $\frac{3.37 - 4.25}{0.275}$ )

= 1 - P( z < -3.2 )

= 1 - 0.0007

= 0.9993

⇒P(X⁻ > 3.37) = 0.9993

∴ we get

Probability that the sample mean carapace length is more than 4.25 inches = 0.9993

6 0

2 years ago