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1 year ago

In a standard normal distribution, what z value corresponds to 17% of the data between the mean and the z value?

1 answer:

hjlf1 year ago

4 0

You're looking for a value $z$ such that

$\mathbb P(0$

Because the distribution is symmetric, the value of $z$ in either case will be the same.

Now, because the distribution is continuous, you have that

$0.17=\mathbb P(0$

The mean for the standard normal distribution is $0$ , and because the distribution is symmetric about its mean, it follows that $\mathbb P(Z$ .

$0.17=\mathbb P(Z$

You can consult a $z$ score table to find the corresponding score for this probability. It turns out to be $z\approx0.4399$ .

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Jerry buys a pack of pencils that cost $3 David buys 4 sets of markers each set of marker also cost 3 what is the total cost of

Marat540 [252]

The total cost of marker is 12

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2 years ago

The U.S. Energy Information Administration (US EIA) reported that the average price for a gallon of regular gasoline is $2.94. T

Anit [1.1K]

Answer:

a) 25

b) 67

c) 97

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.95}{2} = 0.025$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.025 = 0.975$ , so $z = 1.96$

Now, find the margin of error M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample. In this problem, $\sigma = 0.25$

(a) The desired margin of error is $0.10.

This is n when M = 0.1. So

$M = z*\frac{\sigma}{\sqrt{n}}$

$0.1 = 1.96*\frac{0.25}{\sqrt{n}}$

$0.1\sqrt{n} = 1.96*0.25$

$\sqrt{n} = \frac{19.6*0.25}{0.1}$

$(\sqrt{n})^{2} = (\frac{19.6*0.25}{0.1})^{2}$

$n = 24.01$

Rounding up to the nearest whole number, 25.

(b) The desired margin of error is $0.06.

This is n when M = 0.06. So

$M = z*\frac{\sigma}{\sqrt{n}}$

$0.06 = 1.96*\frac{0.25}{\sqrt{n}}$

$0.06\sqrt{n} = 1.96*0.25$

$\sqrt{n} = \frac{19.6*0.25}{0.06}$

$(\sqrt{n})^{2} = (\frac{19.6*0.25}{0.06})^{2}$

$n = 66.7$

Rounding up, 67

(c) The desired margin of error is $0.05.

This is n when M = 0.05. So

$M = z*\frac{\sigma}{\sqrt{n}}$

$0.05 = 1.96*\frac{0.25}{\sqrt{n}}$

$0.05\sqrt{n} = 1.96*0.25$

$\sqrt{n} = \frac{19.6*0.25}{0.05}$

$(\sqrt{n})^{2} = (\frac{19.6*0.25}{0.05})^{2}$

$n = 96.04$

Rounding up, 97

8 0

1 year ago

Every possible cross section of a three dimensional figure is a circle what is that figure

Korolek [52]

A sphere. It is a perfectly circular and even shape, so all cross sections would be circles.

5 0

2 years ago

Read 2 more answers

Find the binomial coefficient: 2012/2011

seropon [69]

²⁰¹²C₂₀₁₁ = (2012)! / [(2011)! (2012-2011)!]

²⁰¹²C₂₀₁₁ = (2012)! / [(2011)! (1)!]

Simplify 2012! / (2011)! = 2012

²⁰¹²C₂₀₁₁ = (2012)! / (1)! = 2012

4 0

1 year ago

Meredith started last week with $1,000 in her checking account. During the week, she wrote the checks below.

bazaltina [42]

Answer:

B. Meredith should have added the value of the paycheck.

Step-by-step explanation:

Meredith correctly identified the paycheck as a deposit (+), but she subtracted it from her balance when she should have added it.

5 0

1 year ago