Write and evaluate the expression. Then, check all that apply.

Find z such that 97.5% of the standard normal curve lies to the left of z. (Enter a number. Round your answer to two decimal pla

fomenos

Answer:

z=1.96

Step-by-step explanation:

Using normal distribution table or technology, 97.5% corresponds to z=1.959964, generally denoted z=1.96, or 1.96 standard deviations above the mean.

(above value obtained from R)

6 0

3 years ago

Suppose that a jewelry store tracked the amount of emeralds they sold each week to more accurately estimate how many emeralds to

RUDIKE [14]

Answer:

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

And for this case the 95% confidence interval is given by (2.13; 2.37)

We have a point of estimate for the sample mean with this formula:

$\bar X = \frac{Upper+ Lower}{2}= \frac{3.37+2.13}{2}= 2.75$

And for the margin of error we have the following estimation:

$ME= \frac{Upper -Lower}{2}= \frac{3.37-2.13}{2}= 0.62$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

And for this case the 95% confidence interval is given by (2.13; 2.37)

We have a point of estimate for the sample mean with this formula:

$\bar X = \frac{Upper+ Lower}{2}= \frac{3.37+2.13}{2}= 2.75$

And for the margin of error we have the following estimation:

$ME= \frac{Upper -Lower}{2}= \frac{3.37-2.13}{2}= 0.62$

5 0

3 years ago

Hi! May I please have some help?

max2010maxim [7]

Steps:
18 x 2
What is that?
You can also think of it as 9 x 4 if that is easier
Then whatever you got for that, add 21 then subtract 12 and add 1

6 0

3 years ago

Read 2 more answers

Use linear approximation to estimate f (2.85 )given that f (3 )equals 2 and f prime (3 )equals 5.

Allisa [31]

Answer:

Step-by-step explanation:

Given that,

f(3) = 2

f'(3) = 5.

We want to estimate f(2.85)

The linear approximation of "f" at "a" is one way of writing the equation of the tangent line at "a".

At x = a, y = f(a) and the slope of the tangent line is f'(a).

So, in point slope form, the tangent line has equation

y − f(a) = f'(a)(x − a)

The linearization solves for y by adding f(a) to both sides

f(x) = f(a) + f'(a)(x − a).

Given that,

f(3) = 2,

f'(3) = 5

a = 3, we want to find f(2.85)

x = 2.85

Therefore,

f(x) = f(a) + f'(a)(x − a)

f(2.85) = 2 + 5(2.85 - 3)

f(2.85) = 2 + 5×-0.15

f(2.85) = 2 - 0.75

f(2.85) = 1.25

5 0

3 years ago

7/8=?/48<br> a.6<br> b.13<br> c.1<br> d.42

ryzh [129]

D) you just multiply the numerator and denominator by 6 to get an equivalent fraction

7 0

3 years ago

Read 2 more answers