Ask question

Ask question

All categories

3 years ago

10

suppose the scores of standardized tests are normally distributed. If the population standard deviation is 2 points, what minimu

m sample size is needed to be 90% confident that the sample mean is within 1 point of the true population mean

1 answer:

Pachacha [2.7K]3 years ago

5 0

minecraft 200peso de comision

You might be interested in

In three math tests, you score 91,95, and 88 points. How many points must you score on the fourth test to have an A average, or

gulaghasi [49]

That already is a 91.1 grade average. If you want to keep that, get a 90 and above. To find your average, add all your test scores up and divide them by how many scores there are. For instance if you add all those scores up you get 274. Divide it by 3 because there are three scores and there is your average!

5 0

3 years ago

Which of the ratios below is equivalent to 3:5? Select all that apply.

antiseptic1488 [7]

Answer:

D

Step-by-step explanation:

3:5 is equivalent(equal) to 15:25.

15÷5 and 25÷5 is equal to 3:5.

Hope this helped!

5 0

3 years ago

The product of a number and 9 less than the number is 90. find the number.

Grace [21]

15 is answer
15-9=6 and 15x6= 90

7 0

3 years ago

Find x in each triangle

Nimfa-mama [501]

Answer:

x=20

Step-by-step explanation:

Since this is a right triangle, we can use the Pythagorean theorem

a^2 + b^2 = c^2

21 ^2 + x^2 = 29^2

441+x^2 =841

Subtract 441 from each side

x^2 = 841-441

x^2 = 400

Take the square root of each side

sqrt(x^2) = sqrt(400)

x = 20

4 0

3 years ago

Read 2 more answers

A ball rolls down an inclined plane such that the distance (in centimeters) that it rolls in t seconds is given by s(t) = 2t^3 +

IRISSAK [1]

The ball's velocity will be represented by the derivative of its distance function:

$s'(t)=6t^2+6t$

Now find the times $t$ for which this is equal to 30, i.e. solve

$6t^2+6t=30\implies t^2+t-5=0$

This has two solutions, $t=-\dfrac{1\pm\sqrt{21}}2$ , but only one is positive and falls in the interval $[0,3]$ . So the velocity reaches 30 cm/s when $t=-\dfrac{1-\sqrt{21}}2\approx1.79$ .

3 0

3 years ago