The mean amount purchased by a typical customer at Churchill's Grocery Store is $27.50 with a standard deviation of $7.00. Assume the distribution of amounts purchased follows the normal distribution. For a sample of 68 customers, answer the following questions

a. What is the likelihood the sample mean is at least $30.00?
b. What is the likelihood the sample mean is greater than $26.50 but less than $30.00?
c. Within what limits will 90 percent of the sample means occur?

Answers

Answer 1

Answer:

a) 0.0016 = 0.16% probability that the sample mean is at least $30.00.

b) 0.8794 = 87.94% probability that the sample mean is greater than $26.50 but less than $30.00

c) 90% of sample means will occur between $26.1 and $28.9.

Step-by-step explanation:

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

Normal probability distribution

When the distribution is normal, we use the z-score formula.

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

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question, we have that:

[tex]\mu = 27.50, \sigma = 7, n = 68, s = \frac{7}{\sqrt{68}} = 0.85[/tex]

a. What is the likelihood the sample mean is at least $30.00?

This is 1 subtracted by the pvalue of Z when X = 30. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem, we have that:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{30 - 27.5}{0.85}[/tex]

[tex]Z = 2.94[/tex]

[tex]Z = 2.94[/tex] has a pvalue of 0.9984

1 - 0.9984 = 0.0016

0.0016 = 0.16% probability that the sample mean is at least $30.00.

b. What is the likelihood the sample mean is greater than $26.50 but less than $30.00?

This is the pvalue of Z when X = 30 subtracted by the pvalue of Z when X = 26.50. So

From a, when X = 30, Z has a pvalue of 0.9984

When X = 26.5

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{26.5 - 27.5}{0.85}[/tex]

[tex]Z = -1.18[/tex]

[tex]Z = -1.18[/tex] has a pvalue of 0.1190

0.9984 - 0.1190 = 0.8794

0.8794 = 87.94% probability that the sample mean is greater than $26.50 but less than $30.00.

c. Within what limits will 90 percent of the sample means occur?

Between the 50 - (90/2) = 5th percentile and the 50 + (90/2) = 95th percentile, that is, Z between -1.645 and Z = 1.645

Lower bound:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]-1.645 = \frac{X - 27.5}{0.85}[/tex]

[tex]X - 27.5 = -1.645*0.85[/tex]

[tex]X = 26.1[/tex]

Upper Bound:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]1.645 = \frac{X - 27.5}{0.85}[/tex]

[tex]X - 27.5 = 1.645*0.85[/tex]

[tex]X = 28.9[/tex]

90% of sample means will occur between $26.1 and $28.9.


Related Questions

I need help with this shi

Answers

x is domain and y is range... 2, 15, 13, 15, 21... youre welcome

One-third x + one-sixth y = 2. When x is 3, 1 x + StartFraction 3 Over 6 EndFraction y = 6. One-half x + three-fourths y = negative 3. When x is negative 2, negative 1 x minus StartFraction 6 Over 4 EndFraction = 6. Negative 1 y = 12.
Continue solving the system of equations.

What is the solution to the system?

(
,
)

Answers

Answer:

(12, -12)

Step-by-Step:

I got it right on Edge 2021

Answer:

its 12,-

12

Step-by-step explanation:

HELPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP

Answers

1/6 of 3 and 1/6 x 3

Select all of the following tables which represent y as a function of x.

Answers

Answer:

the second and third one

Step-by-step explanation:

two y's that are the same can't have 2 outcomes

Help me please! I am in desperate need

Answers

Answer:

C. The coefficients of [tex]x^ay^b[/tex] and [tex]x^by^a[/tex] are equal.

Step-by-step explanation:

The binomial theorem is given as:

[tex](x+y)^n=\sum_{k=0}^{n} \binom{n}{k}x^{n-k}y^k[/tex]

[tex]n-k+k=n[/tex], and the coefficient of these terms are represented by [tex]\binom{n}{k}[/tex].

*Note [tex]\binom{n}{k}=\binom{n}{n-k}=\frac{n!}{k!(n-k)!}[/tex]

Therefore the coefficients of [tex]x^ay^b[/tex] and [tex]x^by^a[/tex] are equal.

Part2
Please help I’ll make u brainly

Answers

Answer:

someone game me that same question but sadly i wasn't able to get the answer sorry for the inconvience

Step-by-step explanation:

Answer:

3. 2nd degree. Leading term:

[tex] {3x}^{2} [/tex]

Leading coefficient: 3x

Part 1:

[tex] {2x}^{2} + 11x + 15[/tex]

Part 2:

[tex] {3x}^{2} - x - 2[/tex]

Part 3:

[tex] - {x}^{2} + 12x + 17[/tex]

(Part 3 should be correct, double check it, I think it cancels out the minuses in the part 2 equation?)

P.S. I forgot to solve the equations on this and the first page, don't forget that and I can leave another answer for those if you need!

Solve the triangle given that a=19 b=16, c=11.

Answers

Answer:

The angles of the triangle are approximately 87.395º, 57.271º and 35.334º.

Step-by-step explanation:

From statement we know all sides of the triangle ([tex]a[/tex], [tex]b[/tex], [tex]c[/tex]), but all angles are unknown ([tex]A[/tex], [tex]B[/tex], [tex]C[/tex]). (Please notice that angles with upper case letters represent the angle opposite to the side with the same letter but in lower case) From Geometry it is given that sum of internal angles of triangles equal 180º, we can obtain the missing information by using Law of Cosine twice and this property mentioned above.

If we know that [tex]a = 19[/tex], [tex]b = 16[/tex] and [tex]c = 11[/tex], then the missing angles are, respectively:

Angle A

[tex]a^{2} = b^{2}+c^{2}-2\cdot b\cdot c \cdot \cos A[/tex] (1)

[tex]A = \cos^{-1}\left(\frac{b^{2}+c^{2}-a^{2}}{2\cdot b\cdot c} \right)[/tex]

[tex]A = \cos^{-1}\left[\frac{16^{2}+11^{2}-19^{2}}{2\cdot (16)\cdot (11)} \right][/tex]

[tex]A \approx 87.395^{\circ}[/tex]

Angle B

[tex]b^{2} = a^{2}+c^{2}-2\cdot a\cdot c \cdot \cos B[/tex] (2)

[tex]B = \cos^{-1}\left(\frac{a^{2}+c^{2}-b^{2}}{2\cdot a\cdot c} \right)[/tex]

[tex]B = \cos^{-1}\left[\frac{19^{2}+11^{2}-16^{2}}{2\cdot (19)\cdot (11)} \right][/tex]

[tex]B\approx 57.271^{\circ}[/tex]

Angle C

[tex]C = 180^{\circ}-A-B[/tex]

[tex]C = 180^{\circ}-87.395^{\circ}-57.271^{\circ}[/tex]

[tex]C = 35.334^{\circ}[/tex]

The angles of the triangle are approximately 87.395º, 57.271º and 35.334º.

PRE CALC HELP!!! 100 PTS AND BRAINLIEST
(the one I chose isn't correct I just accidentally pressed it)

Answers

Hello!

[tex]\large\boxed{\frac{\pi }{4} < x < \frac{5\pi }{4}}[/tex]

To begin, we can solve the inequality:

sin(x) > cos(x)

Divide both sides by cos(x):

sin(x) / cos(x) > 1

tan(x) > 1

x > π/4

However, we can also solve it the other way to produce the end to the interval:

sin(x) > cos(x)

1 > cot(x)

x < 5π/4

Therefore, sin(x) > cos(x) on the interval π/4 < x < 5π/4.

Answer:

π/4 < x < 5π/4.

Find the measure of angle B
(9x+2) (5x-4)

Answers

Answer:

119

Step-by-step explanation:

[tex]due \: to \: Corresponding \: angles \\ (5x - 4) + (9x + 2) = 180 \\ 14x = 182 \\ x = 13 \\ \\ 9.13 + 2 = b \\ b = 119[/tex]

Answer:

In the given figure, we know that (angle B+angle C)=180°.

[tex](9x + 2) + (5x - 4) = 180 \\ 14x - 2 = 180 \\ 14x = 182 \\ \boxed{x = 13}[/tex]

Angle B = (9x+2) = (9×13+2) = (117+2) = 119°.

Ted's taxi service has cabs that can seat 4 people and vans that can seat 15 people. The taxi service can transport a maximum of 134 people in its 17 units. How many vans does Ted's Taci Service have in it's fleet?

A. 19
B. 11
C. 9
D. 6​

Answers

Answer:

D. 6

Step-by-step explanation:

Please help me with my homework!

Linda used a number line to simplify an expression. Which expression did Linda simplify based on the number line?

A. -9+1
B. -1-9
C. -1+(-8)
D. -1-(-8)

Answers

I am pretty sure the answer is c

If a leaky faucet drips one ounce of water per minute approximately how many gallons per day is that

Answers

Answer:

Step-by-step explanation:

1hr=60mins

24hrs in a day

1hr=60oz

60oz x 24hrs =1440 oz

1440oz = 11.25gal

PLEASE MARK BRAILIEST

Harper knows he is 50 yards from school. The map on his phone shows that the school is 34 inch from his current location.
How far is Harper from home, if the map shows the distance as 3 inches?

Answers

if 34 inches = 50 yards then 1 inch = 50/34
so 1 inch = 1.47058824 yards

3 inches = 4.41176471
you can round this number up to 4.41 yards depending on what the paper says

Kendrick walked of a mile in of an hour. How fast did he walk? _____miles per hour​

Answers

Answer:

He walked at 1 mile per hour

Step-by-step explanation:

Answer:

He walked at 1 mph

Step-by-step explanation:

Add the expression. Write the sum in simplest form 3 /x+2 + x+1 / x^2 + 5x + 6

Answers

Answer: ?

Step-by-step explanation:

Answer:

Step-by-step explanation:

[tex]\frac{3}{x+2} +\frac{x+1}{x^2+5x+6} \\=\frac{3}{x+2} +\frac{x+1}{x^2+3x+2x+6} \\=\frac{3}{x+2} +\frac{x+1}{x(x+3)+2(x+3)} \\=\frac{3}{x+2} +\frac{x+1}{(x+3)(x+2)} \\=\frac{3(x+3)+x+1}{(x+3)(x+2)} \\=\frac{3x+9+x+1}{(x+3)(x+2)} \\=\frac{4x+10}{(x+3)(x+2)} \\=\frac{4x+10}{x^2+5x+6}[/tex]

[tex]=\frac{2(2x+5)}{(x+3)(x+2)}[/tex]

In an hyperbola, the fixed points that have a constant difference in distance from the center are called _

A. Asymptotes
B. Centers
C. Foci
D. Vertices

Please select the best answer from the choices provided

OA
OB
OC
OD

Answers

Answer is C. Foci...

The correct answer is C. Foci.

A hyperbola is defined as the flat open curve resulting from the intersection of a right circular cone from a plane not parallel to any of its origins. The line joining the foci of the hyperbola is called the base line.

The perpendicular to the middle of the baseline is called the center line. It becomes apparent that all points of the center line are equidistant from the foci.

Learn more in https://brainly.com/question/15697124

six less than six times a number is 12​

Answers

Answer:

x = 3

equation: 6x - 6 = 12

Step-by-step explanation:

6x - 6 = 12

aka:

6x + -6 = 12

+6. +6

6x = 18

/6. /6

x = 3

check: 6(3) - 6 = 12

18 - 6 = 12

12 = 12

6x-6=12
6(3)-6= 12
18-6=12
12=12
The number is 3

Find the slope of a line parallel to the line through the points. ises 11.3. omplete the following: (c) (10, 6) and (10, 10) ​

Answers

undefined

hope this helps

Answer:

cv vfgvbgfgvd

Step-by-step explanation:

A drag racer has two parachutes, a main and a backup, that are designed to bring the vehicle to a stop (combined with the brakes) after the end of a run. Suppose that the main chute deploys with probability 0 . 95, and that if the main fails to deploy, the backup deploys with probability 0.999.

Required:
a. What is the probability that one of the two parachutes deploys?
b. What is the probability that the backup parachutes deploys?

Answers

Answer:

a. 0.99995 = 99.995% probability that one of the two parachutes deploys

b.0.04995 = 4.995% probability that the backup parachutes deploys

Step-by-step explanation:

a. What is the probability that one of the two parachutes deploys?

Either the first deploys(with probability 95%), or the first does not deploy(probability 5%) and the second does(probability 99.9%). So

[tex]p = 0.95 + 0.05*0.999 = 0.99995[/tex]

0.99995 = 99.995% probability that one of the two parachutes deploys

b. What is the probability that the backup parachutes deploys?

The first does not deploy(probability 5%) and the second does(probability 99.9%). So

[tex]p = 0.05*0.999 = 0.04995[/tex]

0.04995 = 4.995% probability that the backup parachutes deploys

How do you write 3% as a fraction

Answers

Answer: 3/100

Step-by-step explanation:

Answer:

3/100

Step-by-step explanation:

What is the slope of a line that is perpendicular to the line shown on the graph?​

Answers

The answer is C. 1/2

Hope this helps!

С
a
Find all the missing elements:
B
A = 40°
a = 8
А
b = 7
b
B = [?]° C = [ ]° c = [ ]
Round to the nearest tenth.
C С

Answers

Answer:

B=34.2

C=105.8

c=12.0

Step-by-step explanation:

find B using the sine rule

(sin40÷8)=(sinB÷7)

rearrange

sin B= (sin40x7)÷8

sin B=0.562

make sure to use your calculator

then press shift sin to find B

B= 34.2°

to the nearest tenth means to 1 decimal place

sum of angles in a triangle is 180

so 180-(40+34.2)=105.8°=C

use sine rule again to find c

(sin105.8÷c)=(sin40÷8)

rearrange

c= (sin 105.8x8)÷sin40

c=12.0

Help asappppp ? Writing linear Equations?

Answers

Answer:

C=0.75m+3

Step-by-step explanation:

3=flat fee

0.75 per mile

m=mile

c=cost

anyone can u please help me? lol

Answers

Answer:

-1/30

Step-by-step explanation:

just subtract then divide.

(this is simplest form)

        nvm

my bad, i forgot some steps you can delete this answer if wanted.

How to Simplify (7x+2)+(x+8)-2x

Answers

Answer:

Step-by-step explanation:

The answer to this should be 2(3x+5)

The simplified answer of this is 6x+10

I hope I helped you out.

Answer:

P: ()

E: 5^4 (example)

M:x

D: ÷

A:+

S:-

can someone help with 9-12 please ?

Answers

Answer:

9-12 is -3

Step-by-step explanation:

In ΔHIJ, the measure of ∠J=90°, the measure of ∠I=60°, and JH = 80 feet. Find the length of IJ to the nearest foot.

Answers

Answer:

46.2

Step-by-step explanation:

46.188= 46.2

HELP!
What is the scale factor !

Answers

Answer:

A scale factor is usually a decimal which scales, or multiplies, some quantity. In the equation y = Cx, C is the scale factor for x. C is also the coefficient of x, and may be called the constant of proportionality of y to x.

Find the value of X.

Answers

All 3 sides of the triangle are the same, which means all 3 inside angles are the same. Each inside angle is 60 degrees.

We now have 3x = 60

Divide both sides by 3:

x = 60/3

x = 20

Answer:

As in the given figure, all the sides are equal i.e., 5 units

It is a equilateral triangle.

In equilateral triangle all the angles are 60°.

[tex]3x = 60 \\ x = \frac{60}{3} \\ \boxed{x = 20}[/tex]

20 is the right answer.

please help asap will give brainliest !!!

Answers

Step-by-step explanation:

The longest side in a triangle is opposite the largest angle, and the shortest side is opposite the smallest angle.

So the smallest angle is <P.

Hope it may help :)

Other Questions
What political policies did most Southern states oppose? Check all that apply. international treaties adding states to the Union a strong federal government government aid to business protective tariffs Janette has 386 pennies. 58 nickels and 19 dimes If Janette exchanges her coins for dollars, how many dollars will she have? How many cents will remiain? One-third x + one-sixth y = 2. When x is 3, 1 x + StartFraction 3 Over 6 EndFraction y = 6. One-half x + three-fourths y = negative 3. When x is negative 2, negative 1 x minus StartFraction 6 Over 4 EndFraction = 6. Negative 1 y = 12.Continue solving the system of equations.What is the solution to the system?( , ) Look the photo.Plz help! How do you write 3% as a fraction I need a bit of help! Which letter goes where? Story:Death of the unsinkable titanic 4+2(7)= Evaluate can someone plz help im confused In America, who makes the laws?O People elected to serve as presidentPeople elected to serve as governorsO Cabinet membersO People elected to serve in the legislature Read the paragraph below and answer the question that follows.'My name is Jonathan Cross. 2/am a member of the basketball team at Carter High School. Because ofbudget cuts, our school is unable to pay costs for new uniforms for our team. As a result, the team is seekingother sponsors to fund our new uniforms. 5/ am writing to request that you consider sponsoring our team. Asa sponsor, your company name would be featured on our uniforms.Which of the following topics is introduced by the paragraph?O budget cuts and their negative effects on high school athleticso the team's winning recordo the basketball team's need of new uniforms and their desire for sponsorshipO all of the aboveo none of the above What is the value of 2/7 divided by 4/9 Which state chose not to berepresented in the FirstContinental Congress? Word Bank for #4-8: Read the passage and fill in the blanks using the following terms.DiploidGenetic variabilityHaploidMeiosis Deena had 30 dollars to spend on 3 gifts. She spent 10 1 4 dollars on gift A and 5 4 5 dollars on gift B. How much money did she have left for gift C? Which quotation from a Shakespearean sonnet is couplet Why do different places on Earth have different climates? In a plant species, the allele for dark green leaves (D) is dominant over the allele for light green leaves (d). A plant with Genotype (Dd) is crossed with a plant with genotype (did). What percentage of the offspring are expected to be hybrid for the leaf color trait. A 0% B 25%. C.50%. D 75% aluminum has a density of 270 kg/m3. what volume of aluminum would have a mass of 49.9 kg?(unit = m^3) PRE CALC HELP!!! 100 PTS AND BRAINLIEST(the one I chose isn't correct I just accidentally pressed it) Plsssssssssss Help!!!!!Which equation to represent a relationship where Y is a nonlinear function of X? Select all that apply.