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
Elden [556K]
2 years ago
12

The situation is as follows: Smart phones have changed the world and how we spend our time. A group of researchers at BYU want t

o estimate the mean daily number of minutes that BYU students spend on their phones. In fall 2019, they took a random sample of 430 BYU students and found that on average, students spend 312 minutes on their phones with a standard deviation of 54 minutes per day. The plot of the sample data showed no extreme skewness or outliers. Calculate a 96% confidence interval estimate for the mean daily number of minutes that BYU students spend on their phones in fall 2019. Do not round off in the intermediate steps, only the final answer should be rounded off to two decimal places.
Mathematics
1 answer:
Scilla [17]2 years ago
8 0

Answer:

The 96% confidence interval estimate for the mean daily number of minutes that BYU students spend on their phones in fall 2019 is between 306.65 minutes and 317.35 minutes.

Step-by-step explanation:

Confidence interval normal

We have that to find our \alpha level, that is the subtraction of 1 by the confidence interval divided by 2. So:

\alpha = \frac{1 - 0.96}{2} = 0.02

Now, we have to find z in the Ztable as such z has a pvalue of 1 - \alpha.

That is z with a pvalue of 1 - 0.02 = 0.98, so Z = 2.054.

Now, find the margin of error M as such

M = z\frac{\sigma}{\sqrt{n}}

In which \sigma is the standard deviation of the population and n is the size of the sample.

M = 2.054\frac{54}{\sqrt{430}} = 5.35

The lower end of the interval is the sample mean subtracted by M. So it is 312 - 5.35 = 306.65 minutes

The upper end of the interval is the sample mean added to M. So it is 312 + 5.35 = 317.35 minutes

The 96% confidence interval estimate for the mean daily number of minutes that BYU students spend on their phones in fall 2019 is between 306.65 minutes and 317.35 minutes.

You might be interested in
Which equation represents a line which is perpendicular to the line 2x + y = -5?
Gnesinka [82]

Step-by-step explanation:

Given expression;

   2x + y  = -5;

  The given equation must be written in a form where the slope is the negative inverse of the given one.

A line perpendicular to another will have a negative inverse slope.

   2x + y  = -5

  Equation of a straight line is generally written as;

       y  = mx + c

y and x are the coordinates

m is the slope

c is y - intercept

          2x + y  = -5

                 y  = -2x -5

 The slope of the perpendicular = \frac{1}{2}

So,

the new line;

            y  =  \frac{1}{2}x  -5

Any line with slope of  \frac{1}{2} will be perpendicular

7 0
3 years ago
PLEASE HELP EMERGENCY!! IF YOU ARE NOT 100% SURE ABOUT YOUR ANSWER DO NOT ANSWER THEN!! PLEASE!!
Black_prince [1.1K]

Answer:

A -$66.65

Step-by-step explanation:

4.50x 14 = 63.00 in penalties

-63.00 + - 3.65 = -66.65

3 0
3 years ago
Read 2 more answers
A pyramid has a rectangular base of length (3x + 1)cm and width xcm.
sergey [27]

Answer:

The dimension of the base of the Rectangle Pyramid is Length = 10 and Width = 8/3

Step-by-step explanation:

Given

Rectangle Pyramid

Base Length = 3x + 1

Base Width = x

Height = 12

Volume = 96

Required

Dimension of the base of the pyramid

Given that the volume of the pyramid is ⅓ of the base area * the height.

This is represented mathematical as

Volume = ⅓ * base area * height.

Where

Base area = width * length

Base area = (3x + 1) * x

Base area = 3x² + x.

So,

Volume becomes

Volume = ⅓ * (3x² + x) * 12.

Volume = (3x² + x) * 4

Substitute 96 for volume

96 = (3x² + x) * 4

Divide both sides by 4

96/4 = (3x² + x) * 4/4

24 = 3x² + x

Subtract 24 fr both sides

24 - 24 = 3x² + x - 24

0 = 3x² + x - 24

3x² + x - 24 = 0

Expand

3x² + 9x - 8x - 24 = 0

Factorize

3x(x + 3) - 8(x + 3) = 0

(3x - 8)(x + 3) = 0

3x - 8 = 0 or x + 3 = 0

3x = 8 or x = -3

x = 8/3 or x = -3

Recall that

Length = 3x + 1

Width = x

For any of the above expression, x can't be less than 0; so, x = -3 can't be considered.

Substitute x = 8/3

Length = 3x + 1

Length = 3(8/3) + 1

Length = 8 + 1

Length = 9

Width = x

Width = 8/3

Hence, the dimension of the base of the Rectangle Pyramid is Length = 10 and Width = 8/3

7 0
3 years ago
Could somebody please answer this?
jok3333 [9.3K]
Here are the resulting percentages:
LEAH = 3.5%
RATHA = 2.3%
ED = 1.8%
CHRIS = 4.2%
MARY = 2.5%

You arrive at this answer by dividing the bonus by the wages

BONUS/WAGE = PERCENTAGE OF BONUS TO WAGE.

Chris had the greatest percentage of wages in his bonus
3 0
3 years ago
AC=(5x+12) and BD =8x? Can somebody help me to slove it
AleksAgata [21]
To solve this equation from the information given above, I ordered it 5x+12=8x. To solve, I subtracted 5x from each side, canceling the 5x to your left, leaving only the number 12. 8x minus 5x equals 3x. Take 3x and divide on both sides. 3x/3x cancels the 3, leaving 12/3 equals 4. Finally, x equals 4.
3 0
3 years ago
Other questions:
  • Keisha bought cups of coffee and bagels for the people in her office. Each bagel cost $2 and each cup of coffee cost $1.50. Keis
    5·1 answer
  • Using the technique in the model above, find the missing side in this 30°-60°-90° right triangle.
    8·2 answers
  • DIVIDING ALGEBRAIC FRACTIONS
    10·1 answer
  • 2. The part of the conditional following "if" is called the _______________.
    12·1 answer
  • Convert 242 dm to feet. Round to 1 decimal.
    13·1 answer
  • How many digits will be in the quotient of 588 divided by 6 use place value to explain
    10·2 answers
  • An opaque bag contains 3 green marbles, 3 red marbles. If two consecutive marbles are drawn without replacement what is the prob
    8·2 answers
  • Pls help it’s math homework
    6·2 answers
  • Solve for x.<br> 5(x + 1) = 4(X + 8)<br> Ox= 37<br> Ox=7<br> Ox=27<br> Ox=17<br> Help please
    8·1 answer
  • What is the answer to these questions?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!