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
allsm [11]
3 years ago
11

A student records the number of hours that they have studied each of the last 23 days. They compute a sample mean of 2.3 hours a

nd a median of 2.5 hours. When they review their data, they notice that the maximum value was recorded as 10 hours and it should have been 14. they fix this error. When compare to origional dataset, did the IQR:______________.1. Increase2. Decrease3. Stayed the same4. There is no way to tell without actually seeing the data
Mathematics
1 answer:
natita [175]3 years ago
6 0

Answer:

the standard deviation increases

Step-by-step explanation:

Let x₁ , x₂, .   .   .  , x₂₃ be the actual data observed by the student

The sample means  = x₁  +  x₂  +  .   .   .  , x₂₃ / 23

= \frac{x_1 +x_2 +...x_2_3}{23}

= 2.3hr

⇒\sum xi =2.3 \times 23 = 52.9hrs

let x₁ , x₂, .   .   .  , x₂₃  arranged in ascending order

Then x₂₃ was 10  and has been changed to 14

i.e x₂₃ increase to 4

Sample mean  = \frac{x_1 +x_2 +...x_2_3}{23}

\frac{52.9hrs + 4}{23} \\\\= \frac{56.9}{23} \\\\= 2.47

therefore, the new sample mean is 2.47

2) For the old data set

the median is x_1_2(th) values

[\frac{n +1}{2} ]^t^h value

when we use the new data set only x₂₃ is changed to 14

i.e the rest all observation remain unchanged

Hence, sample median = [{x_1_2]^t^h value remain unchange

sample median = 2.5hrs

The Standard deviation of old data set is calculated

=\sqrt{\frac{1}{n-1} \sum (xi - \bar x_{old})^2 } \\\\=\sqrt{\frac{1}{22}\sum ( xi - 2.3)^2 }---(1)

The new sample standard sample deviation is calculated as

= \sqrt{\frac{1}{n-1} \sum (xi-2.47)^2} ---(2)

Now, when we compare (1) and (2)  the square distance between each observation xi and old mean is less than the squared distance between each observation xi and the new mean.

Since,

(xi - 2.3)²  ∑ (xi - 2.47)²

Therefore , the standard deviation increases

You might be interested in
Colin is working to earn some money for a new CD player. On Saturday he earns half as much as he did on Sunday, but twice as muc
Marysya12 [62]

Answer:

Friday=$10 Saturday=$20 Sunday=$40

Step-by-step explanation:

On Friday we can estimate that he earnt $10 so twice as many as that is $20 so on Saturday he could of earnt that much. Finally what is 20 half of? 40 so 10+20+40=$70

3 0
3 years ago
Two ways technology can affect the environment
Lelu [443]
<span>Two ways technology can affect the environment is by air pollution and toixc water</span>
6 0
3 years ago
If BY = 6, YC = 10, AX = 18, then XC = <br> a: 10.8 <br> b:5 <br> c:30 <br> d:48
vampirchik [111]
To answer this item, we assume that the topic is in similar polygons such that the ratio of the corresponding sides should be equal. In this item,

    BY/YC = AX/XC

Substituting the known values,

    6/10 = 18/XC

The value of XC from the equation is 30. The answer is letter C. 
3 0
3 years ago
Read 2 more answers
How to find the inverse of each function <br> for example like this one: <br> h(x)=5/4x
Anton [14]
First rewrite it like this
1. y=5/4x
Then, make X the subject
2.4x=5/y
x=(5/y)÷4
3. Once done, simply replace x with h(x)^-1 and y with x
h(x)^-1= (5/x)÷4
Sorry I'm not very good at rearranging formula but hope this helps :)
4 0
3 years ago
Read 2 more answers
Transversal cuts parallel lines and at points X and Y respectively. The point nearest to C is X, and the point nearest to D is Y
hammer [34]

Answer:  The answer is (B) ∠SYD.


Step-by-step explanation: As mentioned in the question, two parallel lines PQ and RS are drawn in the attached figure. The transversal CD cut the lines PQ and RS at the points X and Y respectively.

We are given four angles, out of which one should be chosen which is congruent to ∠CXP.

The angles lying on opposite sides of the transversal and outside the two parallel lines are called alternate exterior angles.

For example, in the figure attached, ∠CXP, ∠SYD and ∠CXQ, ∠RYD are pairs of alternate exterior angles.

Now, the theorem of alternate exterior angles states that if the two lines are parallel having a transversal, then alternate exterior angles are congruent to each other.

Thus, we have

∠CXP ≅ ∠SYD.

So, option (B) is correct.

5 0
2 years ago
Other questions:
  • For the triangles to be similar by the SSS similarity theorem, what must be the value of y?
    10·2 answers
  • The length of a rectangular picture is 5 inches more than three times the width. Find the dimensions of the picture if it’s peri
    8·1 answer
  • A grocery cart contains eggs for 89¢, bread for 95¢, fruit for $1.79, meat for $2.89, and vegetables for $1.29. What is the tota
    12·1 answer
  • -11 2/3 * (-4 1/5)=
    14·2 answers
  • What is the area of the triangle?
    11·2 answers
  • Factor completely x2 + 20x − 36.
    11·1 answer
  • What is the distance between (−5,−6) and (−3,−8)?
    7·1 answer
  • Mary bought a purse which was marked at 25% off. The original price of the purse was
    7·2 answers
  • If a cylindrical vessel is 15 cm long and its surface area is 650 cm?, set up an
    14·1 answer
  • Todd is 33 years old; his nephew Jacob is 12. In how many years will Jacob be ½ his uncle Todd's age?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!