1answer.
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
hoa [83]
3 years ago
11

The probability model below describes the number of repair calls that an appliance repair shop may receive during an hour. Compl

ete parts a and b below.
Repair Calls 1 2 3 4
Probability 0.1 0.5 0.3 0.1

a. How many calls should the shop expect per hour?
b. What is the standard deviation?
Mathematics
1 answer:
defon3 years ago
3 0

Answer:

a) So, she can expect a 2.4 calls per hour.

b) So, the standard deviation is 0.8.

Step-by-step explanation:

We know that probability model below describes the number of repair calls that an appliance repair shop may receive during an hour.

Repair Calls 1 2 3 4  

Probability 0.1 0.5 0.3 0.1

a) We calculate how many calls should the shop expect per hour.

We get:

E(X)=1\cdot0.1+2\cdot0.5+3\cdot0.3+4\cdot0.1\\\\E(X)=0.1+1+0.9+0.4\\\\E(X)=2.4

So, she can expect a 2.4 calls per hour.

b) We calculate the standard deviation:

\sigma=\sqrt{(1-2.4)^2\cdot 0.1+(2-2.4)^2\cdot 0.5+(3-2.4)^2\cdot 0.3+(4-2.4)^2\cdot 0.1}\\\\\sigma=\sqrt{0.196+0.08+0.108+0.256}\\\\\sigma=\sqrt{0.64}\\\\\sigma=0.8

So, the standard deviation is 0.8.

You might be interested in
-9p-17=10 pls help I do Connexus
marshall27 [118]
P would equal negative three.
7 0
3 years ago
11000 is compounded semiannually at a rate of 12% for 21 years. Find the total amount in the compound interest account
marishachu [46]

\bf ~~~~~~ \textit{Compound Interest Earned Amount}
\\\\
A=P\left(1+\frac{r}{n}\right)^{nt}
\quad
\begin{cases}
A=\textit{accumulated amount}\\
P=\textit{original amount deposited}\dotfill &\$11000\\
r=rate\to 12\%\to \frac{12}{100}\dotfill &0.12\\
n=
\begin{array}{llll}
\textit{times it compounds per year}\\
\textit{semiannually, thus twice}
\end{array}\dotfill &2\\
t=years\dotfill &21
\end{cases}


\bf A=11000\left(1+\frac{0.12}{2}\right)^{2\cdot 21}\implies A=11000(1.06)^{42}\implies A\approx 127127.359416

5 0
3 years ago
Find the area bounded by the curves x = 2y2 and x = 1 - y. Your work must include an integral in one variable.
Sedbober [7]

Answer:

Hello,

in order to simplify, i have taken the inverses functions

Step-by-step explanation:

\int\limits^\frac{1}{2} _{-1} {(-2x^2-x+1)} \, dx \\\\=[\frac{-2x^3}{3} -\frac{x^2}{2} +x]^\frac{1}{2} _{-1}\\\\\\=\dfrac{-2-3+12}{24} -\dfrac{-5}{6} \\\\\boxed{=\dfrac{9}{8} =1.25}\\

4 0
2 years ago
A model airplane is built on the scale of 0.5 inch for every 11 feet. The length of the
Tema [17]

Answer:

9.59 ft

Step-by-step explanation:

\frac{211}{11}

= 19.181818\\multiply\\by\\0.5\\= 9.59

6 0
2 years ago
A store is selling a shirt for 1/4 off the original price of 28. what is the sale price of the shirt
Sedaia [141]
1/4 off means 0.25 * 28
7
Sale price = 28-7
= 21
3 0
3 years ago
Other questions:
  • The shaded portion of the model represents the decimal 0.43. Which decimal completes the statement to make it true? ___ > 0.4
    12·1 answer
  • What is 65,754.59 rounded to the nearest tenth
    14·1 answer
  • Need the answer! Anyone know?
    15·2 answers
  • An 8-pack of juice boxes costs $5. How much do 32 juice boxes cost?
    6·2 answers
  • The formula rho equals m over V, where ρ = density, m = mass, and V = volume, is used to calculate density. Solve this formula f
    7·2 answers
  • Y-intercept=29 x-intercept=29/3
    5·1 answer
  • Help!!!!!!!!!!!!!!!! on 80 and 81
    6·2 answers
  • The top portion of the Washington Monument is a square pyramid. The dimensions are shown in the net to the nearest foot.
    8·2 answers
  • Find the volume of each sphere. Round to the nearest tenth.
    9·1 answer
  • What is the volume of a sphere with a diameter of 7.9 ft
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!