answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Georgia [21]
2 years ago
8

The distribution of the amount of a customer’s purchase at a convenience store is approximately normal, with mean $15.50 and sta

ndard deviation $1.72. Which of the following is closest to the proportion of customer purchase amounts between $14.00 and $16.00 ?
A) 0.19
B) 0.39
C) 0.42
D) 0.61
E) 0.81
Mathematics
1 answer:
viktelen [127]2 years ago
4 0

Answer:

0.42 is closest to the proportion of customer purchase amounts between $14.00 and $16.00

Step-by-step explanation:

Mean = \mu = 15.50

Standard deviation = \sigma = 1.72

We are supposed to find the proportion of customer purchase amounts between $14.00 and $16.00

P(14<x<16)

Formula : z=\frac{x-\mu}{\sigma}

At x = 14

z=\frac{14-15.50}{1.72}

z=-0.8720

Refer the  z table for p value

P(x<14)=0.1922

At x = 16

z=\frac{16-15.50}{1.72}

z=0.290

Refer the  z table for p value

P(x<16)=0.6141

P(14<x<16)=P(x<16)-P(x<14)=0.6141-0.1922=0.42

So, Option C is true

Hence 0.42 is closest to the proportion of customer purchase amounts between $14.00 and $16.00

You might be interested in
What are the solutions of the equation 9x4 – 2x2 – 7 = 0? Use u substitution to solve. tions of the equation 9
skelet666 [1.2K]

Answer:

Step-by-step explanation:

Let u^2=x^4\\u = x^2

Subbing in:

9u^2-2u-7=0

a = 9, b = -2, c = -7

The product of a and c is the aboslute value of -63, so a*c = 63.  We need 2 factors of 63 that will add to give us -2.  The factors of 63 are {1, 63}, (3, 21}, {7, 9}.  It looks like the combination of -9 and +7 will work because -9 + 7 = -2.  Plug in accordingly:

9u^2-9u+7u-7=0

Group together in groups of 2:

(9u^2-9u)+(7u-7)=0

Now factor out what's common within each set of parenthesis:

9u(u-1)+7(u-1)=0

We know this combination "works" because the terms inside the parenthesis are identical.  We can now factor those out and what's left goes together in another set of parenthesis:

(u-1)(9u+7)=0

Remember that u=x^2

so we sub back in and continue to factor.  This was originally a fourth degree polynomial; that means we have 4 solutions.

(x^2-1)(9x^2+7)=0

The first two solutions are found withing the first set of parenthesis and the second two are found in other set of parenthesis.  Factoring (x^2-1) gives us that x = 1 and -1.  The other set is a bit more tricky.  If

9x^2+7=0 then

9x^2=-7 and

x^2=-\frac{7}{9}

You cannot take the square root of a negative number without allowing for the imaginary component, i, so we do that:

x=±\sqrt{-\frac{7}{9} }

which will simplify down to

x=±\frac{\sqrt{7} }{3}i

Those are the 4 solutions to the quartic equation.

5 0
2 years ago
Algebra find the value of x in each figure.
spin [16.1K]

Answer:

38

Step-by-step explanation:

The angle is 90* total. If you subtract 49 you have a 41-degree angle. What plus three equals 41?

3 0
1 year ago
What’s the answer????
alex41 [277]

Answer:

80

Step-by-step explanation:

the formula is base times height the height is 10 and the base is 8 so 10 times 8 equals 80

4 0
2 years ago
Read 2 more answers
What is the value of k in the equation below? 5k - 2k = 12? 1 1/5, 1 5/7, 3, 4
valkas [14]
Hi there!

5k - 2k = 12
Solve for K
3k = 12
Divide both sides by 3
3k/3 = 12/3
k = 4
The correct answer is : 4


I hope that helps!
Brainliest answer :)
8 0
2 years ago
Read 2 more answers
A cup of coffee has approximately 310 mg of caffeine. Each hour, the caffeine in your system decreases by about 35%. How much ca
Alex787 [66]

Answer:

∴35.97 mg caffeine would be left in the system after 5 hours.

Step-by-step explanation:

Given that,

A cup of coffee has approximately 310 mg of caffeine.

Caffeine decrease at a rate 35% per hour.

Exponential Function:

y(t)=y_0(1-r)^t

y(t)= Amount caffeine after t hours

y_0= Initial amount of caffeine

r= rate of decrease

t = Time in hour.

Here y(t)=?, y_0 = 310 mg, r=35%=0.35, t= 5 hours

y(t)=310(1-0.35)^5

      =35.97 mg

∴35.97 mg caffeine would be left in the system after 5 hours.

3 0
2 years ago
Other questions:
  • At the rate of $2.00 per square foot the cost of painting the rectangular board with a semicircular top shown in the figure is $
    8·2 answers
  • If JM = 5x – 8 and LM = 2x – 6, which expression represents JL? 3x – 2 3x – 14 7x – 2 7x – 14
    10·2 answers
  • Estimate the product 8.1 x 4.2
    14·1 answer
  • A​ once-popular children's doll is slowly declining in popularity. The quartic function f (x)equals negative 0.022 x Superscript
    5·1 answer
  • The following formula for the sum of the cubes of the first n integers is proved in Appendix E. Use it to evaluate the limit in
    9·1 answer
  • What is the first step to solve this equation : 11-3x=44
    12·2 answers
  • Students are asked to memorize a list of 100 words. The students are given periodic quizzes to see how many words they have memo
    12·1 answer
  • Sarah kept track of the points she scored during her first five basketball games in the table shown.
    15·1 answer
  • Lila wrote an equation of the cost for printing brochures, where x represents the number of brochures and y represents the total
    6·2 answers
  • If a certain number of Grade IV students share 28 or 39 skill books in Mathematics,there are remainders of 4 and 3 books. What i
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!