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
lbvjy [14]
3 years ago
7

The amount of money spent on textbooks per year for students is approximately normal.

Mathematics
1 answer:
Ostrovityanka [42]3 years ago
4 0

Answer:a

a

   336.04    <  \mu < 443.96

b

  The  margin of error will increase

c

The  margin of error will decreases

d

The 99% confidence interval is  0.4107 <  p  < 0.4293

Step-by-step explanation:

From the question we are  told that

   The sample size  n =  19

    The sample mean is  \= x  = \$\  390

    The  standard deviation is  \sigma =  \$ \  120

 

Given that the confidence level is  95% then the level of significance is mathematically represented as

           \alpha = 100 -  95

          \alpha  =  5 \%

          \alpha  =  0.05

Next we obtain the critical value of \frac{\alpha }{2} from the normal distribution table

    So  

         Z_{\frac{\alpha }{2} } =  1.96

The  margin of error is mathematically represented as

      E =  Z_{\frac{\alpha }{2} } *  \frac{\sigma}{\sqrt{n} }

=>    E = 1.96 *  \frac{120}{\sqrt{19} }

=>   E = 53.96

The 95% confidence interval is  

     \= x  -  E  <  \mu < \= x  +  E

=>   390  -   53.96   <  \mu < 390  -   53.96

=>  336.04    <  \mu < 443.96

When the confidence level increases the Z_{\frac{\alpha }{2} } also increases which increases the margin of error hence the confidence level becomes wider

Generally the sample size mathematically varies with margin of error as follows

         n  \  \ \alpha  \ \  \frac{1}{E^2 }

So if the sample size increases the margin of error decrease

The  sample proportion is mathematically represented as

       \r p  =  \frac{210}{500}

       \r p  = 0.42

Given that the confidence level is 0.99 the level of significance is  \alpha =  0.01

The critical value of \frac{\alpha }{2} from the normal distribution table is  

      Z_{\frac{\alpha }{2} }  =  2.58

  Generally the margin of error is mathematically represented as

       E =  Z_{\frac{\alpha }{2} }*  \sqrt{ \frac{\r p (1- \r p )}{n} }

=>   E =  0.42 *  \sqrt{ \frac{0.42 (1- 0.42 )}{ 500} }

=>     E =  0.0093

The 99% confidence interval  is

     \r p  -  E <  p  < \r p  +  E

     0.42  -  0.0093 <  p  < 0.42  +  0.0093

     0.4107 <  p  < 0.4293

 

You might be interested in
To convert 25 minutes to hours, you would use the ratio 1hour/60minutes?
Talja [164]
Idk but it's 0.416667

cuz 25/60 equals so
7 0
3 years ago
If ABC=PQR, then <br> BC=?
olya-2409 [2.1K]
If ABC=PQR, then
BC=QR
4 0
3 years ago
PLS HELP PLS I REALLY NEED IT!!
frutty [35]

Answer:

Step-by-step explanation:

3 0
2 years ago
Read 2 more answers
The midpoint of FG is (6-4) and the coordinates of point Fare (-3, 6) What are the coordinates of point G?​
lora16 [44]

Answer:

(15,-14)

Step-by-step explanation:

Given that,

The midpoint of FG is (6-4) and the corrdinates of F are (-3,6).

Let (x,y) be the coordinates of point G. Using mid point formula,

\dfrac{x+(-3)}{2}=6\ \text{and}\ \dfrac{y+6}{2}=-4\\\\x-3=12\ \text{and}\ y+6=-8\\\\x=15,\ \text{and}\ y=-14

So, the coordinates of G are (15,-14).

4 0
2 years ago
There are 86400 frames of animation in 1 hour of anime. How many frames are there per second?
a_sh-v [17]

Answer:

1400

Step-by-step explanation:

8 0
3 years ago
Read 2 more answers
Other questions:
  • What is an expression for the calculation 2/3 times the sum of 2/8 and 4/8?
    13·1 answer
  • What does 0.001085 equal to g?
    8·1 answer
  • Simplified product ?
    13·1 answer
  • Which is the closest approximation to the area of the circle?
    13·2 answers
  • Factor the following equation to find its zeros. y = x² - 36
    9·1 answer
  • If g(x) = (24 – x)2 + 7, what is<br> the value of g(6)?<br> O 250<br> O-2<br> O 243<br> O 331
    11·1 answer
  • (17, -13), (17, 8)<br> What is the slope through the line
    9·2 answers
  • Freeeeeee pointssssssss im bored so here ya go
    9·2 answers
  • Question
    11·1 answer
  • Find the mean of 25 numbers if the mean of 15 of them is 18 and the mean of the rest is 13
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!