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
ra1l [238]
3 years ago
8

Need help with this easy math problem

Mathematics
2 answers:
s344n2d4d5 [400]3 years ago
6 0

Answer:

b

Step-by-step explanation:

ki77a [65]3 years ago
4 0

Answer:

its B.

Step-by-step explanation:

You might be interested in
To​ ​ get​ ​ an​ ​ accurate​ ​ result,​ ​ a​ ​ sample​ ​ size​ ​ must​ ​ be
levacccp [35]
At least 30 ..................
8 0
3 years ago
The sum of two numbers is 39. The sum of twice the larger number and three times the smaller number is 93. Find the smaller numb
ExtremeBDS [4]

Answer:3 * (n + 4) = 93

3n + 12 = 93

Subtract 12 to both sides:

3n = 81

Divide 3 to both sides:

n = 27

Step-by-step explanation:

6 0
3 years ago
a survey amony freshman at a certain university revealed that the number of hours spent studying the week before final exams was
Marat540 [252]

Answer:

Probability that the average time spent studying for the sample was between 29 and 30 hours studying is 0.0321.

Step-by-step explanation:

We are given that the number of hours spent studying the week before final exams was normally distributed with mean 25 and standard deviation 15.

A sample of 36 students was selected.

<em>Let </em>\bar X<em> = sample average time spent studying</em>

The z-score probability distribution for sample mean is given by;

          Z = \frac{ \bar X-\mu}{\frac{\sigma}{\sqrt{n} } }} }  ~ N(0,1)

where, \mu = population mean hours spent studying = 25 hours

            \sigma = standard deviation = 15 hours

            n = sample of students = 36

The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X.

Now, Probability that the average time spent studying for the sample was between 29 and 30 hours studying is given by = P(29 hours < \bar X < 30 hours)

    P(29 hours < \bar X < 30 hours) = P(\bar X < 30 hours) - P(\bar X \leq 29 hours)

      

    P(\bar X < 30 hours) = P( \frac{ \bar X-\mu}{\frac{\sigma}{\sqrt{n} } }} } < \frac{ 30-25}{\frac{15}{\sqrt{36} } }} } ) = P(Z < 2) = 0.97725

    P(\bar X \leq 29 hours) = P( \frac{ \bar X-\mu}{\frac{\sigma}{\sqrt{n} } }} } \leq \frac{ 29-25}{\frac{15}{\sqrt{36} } }} } ) = P(Z \leq 1.60) = 0.94520

                                                                    

<em>So, in the z table the P(Z </em>\leq<em> x) or P(Z < x) is given. So, the above probability is calculated by looking at the value of x = 2 and x = 1.60 in the z table which has an area of 0.97725 and 0.94520 respectively.</em>

Therefore, P(29 hours < \bar X < 30 hours) = 0.97725 - 0.94520 = 0.0321

Hence, the probability that the average time spent studying for the sample was between 29 and 30 hours studying is 0.0321.

7 0
3 years ago
4xy-28x = 16 work and answer please
algol [13]
Lol do your own work. Pay attention in class, it'll pay off ;)
6 0
3 years ago
Can anyone explain to me how I should go about figuring this out?
docker41 [41]

Answer:

First paragraph of being a bit of an error on ep of being a bit more than

5 0
3 years ago
Other questions:
  • What is the mean of the probability distribution?
    13·1 answer
  • Benton has an extension ladder than can only be used at a length of 10 feet, 15 feet, or 20 feet. He places the base of the ladd
    7·1 answer
  • 3.467 rounded to the nearest tenth of an ounce
    13·1 answer
  • If two planes intersect, they intersect in exactly one ?
    6·2 answers
  • 243.875 round to the nearest hundred
    11·2 answers
  • I will send a picture of it thanks​
    6·2 answers
  • Which expression defines the arithmetic series 4+8+12+... for four terms?
    13·1 answer
  • The graphs of four quadratic equations are shown. Identify the number of real solutions of each equation by
    12·1 answer
  • A circle with radius of 1 cm sits inside a 11 cm x 12 cm rectangle. What is the area of the shaded region? Round your final answ
    7·1 answer
  • PLS HELP ME!! THIS IS URGENT!!!
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!