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
Slav-nsk [51]
3 years ago
8

A publishing company has just published a new college textbook. Before the company decides the price at which to sell this textb

ook, it wants to know the average price of such textbooks in the market. The research department at the company took a sample of 25 comparable textbooks and collected information on their prices. This information produced a mean of $145 for this sample. It is known that the standard deviation of all such textbooks is $35 and the population of such prices is normal.
a. What is the point estimate of the mean price of all such college textbooks?

b. Construct a 90% confidence interval for the mean price of all such college textbooks.
Mathematics
1 answer:
Kobotan [32]3 years ago
8 0

Answer:b

Step-by-step explanation:

You might be interested in
Cara has $25 to buy dry pet food a pound of dog food costs $2 and treats are $1 apiece if she buys 9 pounds of food the greatest
zzz [600]

Cost of each pound of dog food = $2 .

Total cost of 9 pounds of dog food = 9 * 2 = $18.

Let us assume number of treats she can buy = t.

Cost of each treat = $1.

Cost of t number of treats = 1*t = 1t .

Total money Cara has = $25.

We can setup an inequality as,

Total cost of dog food + total cost of t number of treats ≤ 25.

18 + 1t ≤ 25.

Subtracting 18 from both sides, we get

18 + 1t -18  ≤ 25-18.

1t ≤ 7 or t ≤ 7.

So, she can purchase 7 or less treats.

5 0
3 years ago
The scores on the LSAT are approximately normal with mean of 150.7 and standard deviation of 10.2. (Source: www.lsat.org.) Queen
faltersainse [42]

Answer:

a=150.7 -0.385*10.2=146.773

So the value of height that separates the bottom 35% of data from the top 65% (Or the 35 percentile) is 146.7.  

Step-by-step explanation:

1) Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

2) Solution to the problem

Let X the random variable that represent the  scores on the LSAT of a population, and for this case we know the distribution for X is given by:

X \sim N(150.7,10.2)  

Where \mu=150.7 and \sigma=10.2

We want to find a value a, such that we satisfy this condition:

P(X>a)=0.65   (a)

P(X   (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.  

As we can see on the figure attached the z value that satisfy the condition with 0.35 of the area on the left and 0.65 of the area on the right it's z=-0.385. On this case P(Z<-0.385)=0.35 and P(Z>-0.385)=0.65

If we use condition (b) from previous we have this:

P(X  

P(z

But we know which value of z satisfy the previous equation so then we can do this:

Z=-0.385

And if we solve for a we got

a=150.7 -0.385*10.2=146.773

So the value of height that separates the bottom 35% of data from the top 65% (Or the 35 percentile) is 146.7.  

5 0
3 years ago
Read 2 more answers
Find the geometric proof
GrogVix [38]

Answer:

See Explanation

Step-by-step explanation:

Line l is bisector of MO... (given)

\therefore MN = NO.... (1)

\because MN + NO = MO..(M-N-O)

\therefore NO + NO = MO..[From \:(1)]

\therefore 2NO = MO

\therefore NO = \frac{1}{2} MO

\therefore NO = \frac{1}{2}\times 24..(\because MO=24)

\therefore NO =12

Thus Proved

6 0
3 years ago
Read 2 more answers
There are 130 m&amp;m's in a bag. there are half as many green as red. the number of blue is equal to the number of red and gree
AleksandrR [38]
Let x = red
Let 0.5x = green
Let (x) + (0.5x) = 1.5x = blue
Let 0.5(1.5x) = 0.75x = yellow
Let 0.75x + 4 = brown

(x) + (0.5x) + (1.5x) + (0.75x) + (0.75 + 4) = 130
x + 0.5x+ 1.5x + 0.75x + 0.75 + 4 = 130
4.5x + 4 = 130
4.5x = 126
x = 28

Use this value to calculate the other required numbers.
red = 28
green = 0.5x = 0.5(28) = 14
blue = 1.5x = 1.5(28) = 42
yellow = 0.75x = 0.75(28) = 21
brown = 0.75x + 4 = 0.75(28) + 4 = 25
8 0
3 years ago
Answer this please!!!<br><br> During what times is Ann stopped? Give a reason to support your answer
quester [9]

whenever the line drops to the bottom of the graph the reason is because her speed drops to 0

5 0
3 years ago
Read 2 more answers
Other questions:
  • The function f(x)=log[7]x is increasing. True or false
    8·2 answers
  • The bacteria took 1 hour and 40 minutes to fill the initial bottle. Explain how it only took 10 minutes to fill 3 additional emp
    15·2 answers
  • Subtraction of two real numbers may be defined of what operation
    14·1 answer
  • Heather is making a blanket for her baby and is going to put a ribbon border around it. The blanket will be 3 feet by 5 feet. Th
    13·1 answer
  • Adding &amp;<br> -100% +0.58 =<br> ???
    5·1 answer
  • rows of chairs are set out for a wedding. there are 6 chairs in the first row, 14 chairs in the second row, and 22 chairs in the
    6·1 answer
  • A store spends 30% of its budget on maintenance. Its yearly budget is $150,000. Hiw much is spent on maintenance
    7·2 answers
  • Jess jogs at a rate of 6 miles per hour. The next time she jogs she increases her speed to a rate of 7 mile per hour. How long w
    13·1 answer
  • Use inverse operations to solve the equation.<br><br> −4x = 52
    5·2 answers
  • Use prime factors to find hcf of 18 12 56​
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!