Phonics is an instructional method in which children are taught to connect sounds with letters or groups of letters. A sample of 141 first-graders who were learning English were asked to identify as many letter sounds as possible in a period of one minute. The average number of letter sounds identified was 34.09 with a standard deviation of 23.44
Construct a 90% confidence interval for the mean number of letter sounds identified in one minute. Round the answers to at least two decimal places A 90% confidence interval for the mean number of letter sounds identified in one minute is:______

Answer:

A 90% confidence interval for the mean number of letter sounds identified in one minute is: (30.84, 37.34).

Step-by-step explanation:

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

[tex]\alpha = \frac{1 - 0.9}{2} = 0.05[/tex]

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

That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 1.645\frac{23.44}{\sqrt{141}}[/tex]

[tex]M = 3.25[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 34.09 - 3.25 = 30.84.

The upper end of the interval is the sample mean added to M. So it is 34.09 + 3.25 = 37.34.

A 90% confidence interval for the mean number of letter sounds identified in one minute is: (30.84, 37.34).

I need help on number 10 plz

Find the missing lengths.

Hello Good morning can someone give me the answer of this operation?

39 + 1 - 24 / 6=

Also can you tell me the order? :> Thanks!!

whats 2+2 UnU thats a hard one ToT

Rashard is a running back on his football team. He rushed for 418 yards in
the first five games of the season. At this rate, how many yards would he
rush for in 16 games? *

Two numbers have a difference of 12. The smaller of the two numbers is 3 less than double the other. What are the two numbers?

Using the data points below, what is the equation of the linear function that can be used to
model the situation: (1 week, 4 miles), ( 8 weeks, 11 miles)

A.y=x-3
B.y=x+3
C.y=2x+3
D.y=2x-3

Con la información que se encuentra a continuación completar la tabla sobre el valor posicional de los números.
- Carmen sabe que la población de la provincia de Tungurahua es de 581389 habitantes y desea conocer el valor posicional de cada número que forma la cantidad de pobladores.
CM DM UM C D U
b) Descompongo el número de pobladores de la provincia de Tungurahua
....................................................................................................................
c) Escribo el número en letras ................................................

PLEASE HELP ILL GIVE BRAINLIEST

do it and I give 100 points​

If a1 = 6 and an
-5an-1 + 4 then find the value of a4.


Help

You have $10. If you and 3 of your friends want to go to the movies, what does the ticket price need to be for you to be able to buy all 4 tickets?

Plz help me well mark brainliest if correct!!...

Need help on the picture i attached

How is finding the volume of prisms a bit like slicing a loaf of bread?​

The rectangle below has an area of zº +82 + 15 square meters and a width of 2 + 3 meters.
What expression represents the length of the rectangle?
Length
2 +3
2° +8x + 15
Length
meters

Brad is cutting logs. He has 4 logs. Brad will cut each log by 12

If f(1)=1, f(2)=4 and f(n)=3f(n-1)-f(n-2) then find the value of f(4).

Please look at the image

Find the measure of angle 3

give the other person brainiest please

There are six households in a rural community. Each household earns $40,000 per year. Suppose that a new resident builds a mansion in the community and that the income in the new household is $4 million per year. After the new resident arrives, the median household income has _____, and the mean household income has _____. increased; increased not changed; increased not changed; not changed increased; not changed

Please help math thank you!!!

PLSSS HELP PANICKING
The sum of Alex and John's money is $48. Alex has $3 more than twice the amount John has. How much money do they each have? ​

Lines that appear to be tangent are tangent. If O is the center of the circle, what is the value of x?

A. 240°
B. 60°
C. 140°
D. 120°

How many solutions does the following equation have? -2(-4x + 7) = -2 + 4x​

5th grade math. correct answer will be marked brainliest

Use side ratios to determine if the triangles in each pair are similar. If so, complete the similarity statement. NO LINKS!!!​

3 toys cost x kobo. How many toys can be bought with #3.00?​

What is the area of the circle? *.