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
Dafna11 [192]
3 years ago
12

The reported average cost per workbook at a large college is $27.50. A professor claims that the actual average cost per workboo

k is higher than $27.50. A sample of 44 different workbooks has an average cost of $28.90. The population standard deviation is known to be $5.00. Can the null hypothesis be rejected at alpha= 0.05?
Mathematics
1 answer:
nadezda [96]3 years ago
6 0

Answer:

We conclude that the actual average cost per workbook is higher than $27.50.

Step-by-step explanation:

We are given the following in the question:

Population mean, μ = $27.50

Sample mean, \bar{x} = $28.90

Sample size, n = 44

Alpha, α = 0.05

Population standard deviation, σ = $5.00

First, we design the null and the alternate hypothesis

H_{0}: \mu = 27.50\text{ dollars}\\H_A: \mu > 27.50\text{ dollars}

We use one-tailed z test to perform this hypothesis.

Formula:

z_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{\sigma}{\sqrt{n}} }

Putting all the values, we have

z_{stat} = \displaystyle\frac{28.90 - 27.50}{\frac{5.00}{\sqrt{44}} } = 1.8573

Now, z_{critical} \text{ at 0.05 level of significance } = 1.64

Since,  

z_{stat} > z_{critical}

We reject the null hypothesis and accept the alternate hypothesis.

Thus, we conclude that the actual average cost per workbook is higher than $27.50.

You might be interested in
Thirty students in the fifth grade class listed their hair and eye colors in the table below: Brown hair Blonde hair Total Green
Mars2501 [29]

Answer:

No, the events "brown hair" and "brown eyes" are not  independent.

Step-by-step explanation:

The table that represents the  hair and eye colors of thirty students of the fifth grade are given in table as:

                         Brown hair          Blonde hair              Total

Green eyes           9                       6                               15

Brown eyes          10                       5                              15

Total                     19                        11                             30

No, the events  "brown hair" and "brown eyes" are not independent.

Since, two events A and B are said to be independent if:

P(A∩B)=P(A)×P(B)

where P denotes the probability of an event.

Here we have:

A= students having brown hair.

B= students having brown eyes.

A∩B= students having both brown hair and brown eyes.

Now,

P(A)=19/30  (ratio of addition of first column to the total entries)

P(B)=15/30  ( ratio of addition of second row to the total entries)

Also,

P(A∩B)=10/30

Now as:

P(A∩B) ≠ P(A)×P(B)

Hence, the two events are not independent.

8 0
2 years ago
Which of following equations are identities. Check all that apply.
igomit [66]
I think answer should be d. Please give me brainlest I hope this helps
4 0
3 years ago
Read 2 more answers
When are two distinct lines parallel?
sergey [27]

Answer:

if the line keeps going and theynever touch

Step-by-step explanation:

8 0
2 years ago
Read 2 more answers
F(x) = 3x + 12, g(x) = 3x - 1;<br> =<br> =<br> Find (fºg)(x).
MissTica

\text{Given that,}\\\\f(x) = 3x +12, ~ ~ g(x) = 3x -1\\\\(f \circ g)(x)\\\\=f(g(x))\\\\=f(3x-1)\\\\=3(3x-1) +12\\\\=9x - 3 +12\\\\=9x +9\\\\=9(x+1)

3 0
2 years ago
For every 140 feet that Kelly rides on her bicycle, the wheels turn 20 times. About how many times do the wheels turn in 5 miles
Mars2501 [29]

Answer: The wheels turn about 3771 times in 5 miles.

Step-by-step explanation:

Given, Kelly rides on her bicycle such that the number of times wheels turn for every 140 feet = 20

Turns for every feet = \dfrac{20}{140}=\dfrac{1}{7} ...(i)

To find : Number of times wheels turn in 5 miles.

Since , 1 mile = 5,280 feet

Then, 5 miles = 5 x (5,280 feet) = 26,400 feet

Now , Number of times the wheels turn in 26,400 feet = 26400 x (Turns for every feet)

26400\times\dfrac{1}{7}=3771.42857143\approx3771   [From (i)

Hence, the wheels turn about 3771 times in 5 miles.

5 0
3 years ago
Other questions:
  • One of my students got 95, 98, and 32 for the two Principal tests and for the final test. a What is the average of her three tes
    8·2 answers
  • Α-(α-90°)=(α-180°)-α <br> Pls help!
    11·1 answer
  • Write a recursive definition for the sequence 14, 10, 6, 2...
    5·2 answers
  • Noah and Kate's are shopping for new guitar strings in a music store Noah buys two packs of strings Kate buys two packs of strin
    10·2 answers
  • How many 3/4 are in 3?
    9·1 answer
  • Evaluate 7y - 3y for y=3
    12·2 answers
  • How many 1/2 inch cubes can fit in a rectangular prisim with length of 2 height of 3/2 and width of 1.
    7·1 answer
  • Please please help me answer this
    13·1 answer
  • 2) About how many students do not prefer non- fiction?
    5·1 answer
  • a golf course placed an order of 5075 golf balls if there are 7 balls in each package how many packages did the golf course orde
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!