A bag contains 2 white marbles abd six black marbles.

There are many ways to measure the reading ability of children. Research designed to improve reading performance is dependent on

ELEN [110]

Answer:

A 90% confidence interval to estimate the mean DRP score in Henrico County Schools is =32±2.7280

i.e. C.I. [29.3,34.7]

Hence the results are not significant.

Step-by-step explanation:

Given:

Total no of students =44

True mean =32

Standard deviation=11

And all 4 students score also given.

To Find:

90 % confidence interval and conclusion on it.

Solution:

Here for C.I. we required mean, standard deviation and no of students.

So mean =32,S.D.=11 and n=44

Therefore , For 90 % interval Zscore is Z=1.645

C.I.=mean±Z[Standard deviation/Sqrt(n)]

=32±1.645[11/Sqrt(44)]

=32±1.645[1.6583]

=32±2.7280

i.e. C.I. [29.3,34.7]

Now Here to commit on calculated interval we should check value of Z-score

So we need to calculate the sample mean.

Sample mean =Sum of all values /Total no of values.

=[40+ 26 +39+ 14+ 42+ 18 +25+ 43+ 46 +27 +19+ 47+ 19 +26+ 35 +34+ 15+ 44 40+ 38+ 31+ 46 +52 +25+ 35 +35+ 33 +29 +34 +41 +49+ 28+ 42+ 47 +35 +48 +22 33+ 41 +51 +27 +14+ 54 +45]/44

=34.86

Z-score=(sample mean -true mean)/[standard deviation/Sqrt(n)]

=(34.86-32)/[11/Sqrt(44)]

Z=1.72465

For ,

P(Z≥1.72465)=0.08544

For 0.05 significance level the results are not significant at p<0.01.

Researcher claimed mean is not correct upto 0.05 significant level

i.e calculated mean and Sample mean are different.

Hence the results are not significant.

6 0

3 years ago

If you could help me with this math packet,It would be great help

lapo4ka [179]

2.485 is round to 450 and 450 divide by 15 equals 30. 485 divide by 15 32 r 5

4 0

3 years ago

I have like 20 minutes please help<img src="https://tex.z-dn.net/?f=x%5E%7B2%7D-7x%2B10%3D0" id="TexFormula1" title="x^{2}-7x+10

Mandarinka [93]

Answer: Hmm Ok i do this-

Step-by-step explanation:

Wait are we trying to find x?

Ok so for the first one x = 5 and for the second one x = 2

3 0

3 years ago

Samantha has 4 1/2 gallons of lemonade for her daughter’s birthday party. Each gallon of lemonade contains 1.5 grams of fat. How

Lubov Fominskaja [6]

Answer:

6.75 grams

Step-by-step explanation:

Total amount of lemonade with Samantha = 4 1/2 gallons

= (4*2 + 1)/2 gallons = 9/2 gallons = 4.5 gallons

Amount of fat in 1 gallon of lemonade = 1.5 grams

To find amount of fat in 4.5 gallons lemonade

we multiply both side of equation with 4.5

Amount of fat in 1*4.5 gallon of lemonade = 1.5*4.5 grams = 6.75 grams

Thus,

there is 6.75 grams of fat in all the lemonade Samantha has for the party

3 0

3 years ago

Two sides of a parallelogram measure 60 centimeters and 40 centimeters. If one angle of the parallelogram measures 1320, find th

UkoKoshka [18]

Answer:

b. about 91.7 cm and 44.6 cm

Step-by-step explanation:

The lengths of the diagonals can be found using the Law of Cosines.

Consider the triangle(s) formed by a diagonal. The two given sides will form the other two sides of the triangle, and the corner angles of the parallelogram will be the measure of the angle between those sides (opposite the diagonal).

For diagonal "d" and sides "a" and "b" and corner angle D, we have ...

d² = a² +b² -2ab·cos(D)

The measure of angle D will either be the given 132°, or the supplement of that, 48°. We can use the fact that the cosines of an angle and its supplement are opposites. This means the diagonal measures will be ...

d² = 60² +40² -2·60·40·cos(D) ≈ 5200 ±4800(0.66913)

d² ≈ {1988.2, 8411.8}

d ≈ {44.6, 91.7} . . . . centimeters

The diagonals are about 91.7 cm and 44.6 cm.

4 0

3 years ago