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
Korolek [52]
2 years ago
9

Weight of a rock: In a geology course, students are learning to use a balance scale to accurately weigh rocks. One student plans

to weigh a rock 20 times and then calculate the average of the 20 measurements to estimate her rock's true weight. A second student plans to weigh a rock 5 times and calculate the average of the 5 measurements to estimate his rock's true weight. The student who weighs his rock 5 times uses the mean to calculate the 95% confidence interval for the rock weight (in grams). His interval is (25.2, 29.1). What does a 95% confidence interval for rock weight tell us in this case
Mathematics
1 answer:
statuscvo [17]2 years ago
7 0

Answer:

The student who weighted the rock 5 times has a 95% confidence interval of (25.2, 29.1) which is guaranteed to be more wider (less precise) than the other student who weighted the rock 20 times.

Step-by-step explanation:

What is Confidence Interval?

The confidence interval represents an interval that we can guarantee that the target variable will be within this interval for a given confidence level.  

The confidence interval is given by

CI = \bar{x} + t_{\alpha/2}(\frac{\sigma}{\sqrt{n} } ) \\

Where \bar{x} is the mean weight \sigma is the standard deviation t_{\alpha/2} is the critical value from t-table and n is the sample size.

The term t_{\alpha/2}(\frac{\sigma}{\sqrt{n} } ) is known as margin of error.

As the sample size is decreased the corresponding margin of error increases which results in wider confidence interval which means smaller precision.

The student who weighted the rock 5 times has a 95% confidence interval of (25.2, 29.1) which is guaranteed to be more wider (less precise) than the other student who weighted the rock 20 times.

We can say with 95% confidence that the true mean weight of the rock is within the interval of (25.2, 29.1).

You might be interested in
How do you find the exterior angle of a polygon?
trasher [3.6K]

The sum of the measures of the interior angles of a polygon with n sides is (n – 2)180.

The measure of each interior angle of an equiangular n-gon is.

If you count one exterior angle at each vertex, the sum of the measures of the exterior angles of a polygon is always 360°.

7 0
3 years ago
Um comerciante comprou um lote de cabos e quer colocá-los à venda em pedaços, o maior possível, com o mesmo comprimento e sem ha
Aleks [24]

Answer:

12

Step-by-step explanation:

The computation of the size of the customers is shown below:

Here we find the greatest common divisor of the given numbers

96, 60, 84 ÷ 2

48, 30, 42  ÷ 2

24, 15, 21 ÷ 2

12, 15, 21 ÷ 2

6, 15, 21 ÷ 2

3, 15, 21  ÷ 3

1, 5, 7 ÷ 5

1, 1, 7 ÷ 7

1, 1, 1

By this there are three numbers i.e. 2, 2 and 3

So, the lease common denominator is

= 2 × 2 × 3

= 12

6 0
2 years ago
X=17-4y<br> y=x-2<br> answer by substitution
GaryK [48]

Answer:

(5,3)

Step-by-step explanation:

x=17-4y

x=17-4x+8

x=25-4x

5x=25

x=5

y=x-2

y=5-2

y=3

(5,3)

5 0
3 years ago
The blades of a windmill turn on an axis that is 35 feet above the ground. The blades are 10 feet long and complete two rotation
7nadin3 [17]
<span>It could be C. If the blade spends twice in a minute, it would be 30 seconds. 30=2pi/B=pi/15. </span>
6 0
2 years ago
Read 2 more answers
Fiona has to choose a bouquet for her wedding. The probability that she uses red roses is 98%, the probability that she uses orc
tekilochka [14]
0.84: you would do .82/.98 (the probability of orchids and roses divided by probability of roses)
7 0
2 years ago
Other questions:
  • Ratio of 1/16 to 1/16
    12·1 answer
  • The baltimore ravens kansas city chiefs
    8·2 answers
  • What is the measurement of B in this picture
    8·1 answer
  • What is 26 divided by 988
    9·1 answer
  • What are the first three terms of the sequence defined by the following equation?
    13·2 answers
  • Heeeeeeeeeeeelllllllllllllpppppppppppppp​
    7·1 answer
  • a bug travels up a tree, from the ground, over a 30-second invertal. It travels fast at first, and then it slows down. It stops
    8·1 answer
  • Needed ASAP for tonight, 10 quick homework questions
    12·1 answer
  • Suppose f(×) = 2^×, sketch a graph of f(×) and f^-1(×)​
    10·1 answer
  • Please help I need the right answer and I will mark you as brainlist if done right
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!