Ask question

Ask question

All categories

3 years ago

12

Grace was given the description “three less than the quotient of a number squared and nine, increased by eight” and was asked to

evaluate it when n = 6. Her work is shown below.
In which step did she make an error?
step 1
step 2
step 4
step 5

2 answers:

Olegator [25]3 years ago

8 0

Answer:

step 3

Step-by-step explanation:

zheka24 [161]3 years ago

4 0

Step 4 I hope this helps

You might be interested in

Determine the t critical value(s) that will capture the desired t-curve area in each of the following cases: a. Central area 5 .

Flauer [41]

Answer:

a) "=T.INV(0.025,10)" and "=T.INV(1-0.025,10)"

And we got $t_{\alpha/2}=-2.228 , t_{1-\alpha/2}=2.228$

b) "=T.INV(0.025,20)" and "=T.INV(1-0.025,20)"

And we got $t_{\alpha/2}=-2.086 , t_{1-\alpha/2}=2.086$

c) "=T.INV(0.005,20)" and "=T.INV(1-0.005,20)"

And we got $t_{\alpha/2}=-2.845 , t_{1-\alpha/2}=2.845$

d) "=T.INV(0.005,50)" and "=T.INV(1-0.005,50)"

And we got $t_{\alpha/2}=-2.678 , t_{1-\alpha/2}=2.678$

e) "=T.INV(1-0.01,25)"

And we got $t_{\alpha}= 2.485$

f) "=T.INV(0.025,5)"

And we got $t_{\alpha}= -2.571$

Step-by-step explanation:

Previous concepts

The t distribution (Student’s t-distribution) is a "probability distribution that is used to estimate population parameters when the sample size is small (n<30) or when the population variance is unknown".

The shape of the t distribution is determined by its degrees of freedom and when the degrees of freedom increase the t distirbution becomes a normal distribution approximately.

The degrees of freedom represent "the number of independent observations in a set of data. For example if we estimate a mean score from a single sample, the number of independent observations would be equal to the sample size minus one."

Solution to the problem

We will use excel in order to find the critical values for this case

Determine the t critical value(s) that will capture the desired t-curve area in each of the following cases:

a. Central area =.95, df = 10

For this case we want 0.95 of the are in the middle so then we have 1-0.95 = 0.05 of the area on the tails. And on each tail we will have $\alpha/2=0.025$ .

We can use the following excel codes:

"=T.INV(0.025,10)" and "=T.INV(1-0.025,10)"

And we got $t_{\alpha/2}=-2.228 , t_{1-\alpha/2}=2.228$

b. Central area =.95, df = 20

For this case we want 0.95 of the are in the middle so then we have 1-0.95 = 0.05 of the area on the tails. And on each tail we will have $\alpha/2=0.025$ .

We can use the following excel codes:

"=T.INV(0.025,20)" and "=T.INV(1-0.025,20)"

And we got $t_{\alpha/2}=-2.086 , t_{1-\alpha/2}=2.086$

c. Central area =.99, df = 20

For this case we want 0.99 of the are in the middle so then we have 1-0.99 = 0.01 of the area on the tails. And on each tail we will have $\alpha/2=0.005$ .

We can use the following excel codes:

"=T.INV(0.005,20)" and "=T.INV(1-0.005,20)"

And we got $t_{\alpha/2}=-2.845 , t_{1-\alpha/2}=2.845$

d. Central area =.99, df = 50

For this case we want 0.99 of the are in the middle so then we have 1-0.99 = 0.01 of the area on the tails. And on each tail we will have $\alpha/2=0.005$ .

We can use the following excel codes:

"=T.INV(0.005,50)" and "=T.INV(1-0.005,50)"

And we got $t_{\alpha/2}=-2.678 , t_{1-\alpha/2}=2.678$

e. Upper-tail area =.01, df = 25

For this case we need on the right tail 0.01 of the area and on the left tail we will have 1-0.01 = 0.99 , that means $\alpha =0.01$

We can use the following excel code:

"=T.INV(1-0.01,25)"

And we got $t_{\alpha}= 2.485$

f. Lower-tail area =.025, df = 5

For this case we need on the left tail 0.025 of the area and on the right tail we will have 1-0.025 = 0.975 , that means $\alpha =0.025$

We can use the following excel code:

"=T.INV(0.025,5)"

And we got $t_{\alpha}= -2.571$

8 0

3 years ago

2. For the graph, find AB to the nearest tenth<br> y<br> 8<br> А<br> 6<br> B

zheka24 [161]

Answer:

10.8

Step-by-step explanation:

AB can be calculated using the formula $d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$

The coordinates of A are when x = -2, y = -2

At B, x = 8, y = -6

Let,

$A(-2, -2) = (x_1, y_1)$

$B(8, -6) = (x_2, y_2)$

Plug the values into the formula.

$AB = \sqrt{(8 - (-2))^2 + (-6 -(-2))^2}$

$AB = \sqrt{(8 + 2)^2 + (-6 + 2)^2}$

$AB = \sqrt{(10)^2 + (-4)^2}$

$AB = \sqrt{100 + 16}$

$AB = \sqrt{116} = 10.8$ nearest tenth

7 0

3 years ago

College student makes decorative Styrofoam Lions and Husky's which she sells each year. Each one uses 8 oz of Styrofoam and take

Travka [436]

Answer:

She should make 122 Styrofoam lions and 268 Styrofoam Husky's

The maximum profit, she makes is $1109

Step-by-step explanation:

The given information are;

The volume required to make each lion = 8 oz

The time it takes to make each lion = 35 minutes

The amount of profit each lion brings = $2.50

The volume required to make each Husky = 12 oz

The time it takes to make each Husky = 20 minutes

The amount of profit each Husky brings = $3

Let the number of lion Styrofoam cups she makes = x

Let the number of Husky Styrofoam cups she makes = y

Therefore, we have;

x × 35 + y × 20 = 9650..........(1)

x × 8 + y × 12 = 3840.............(2)

Dividing equation (2) by 8 and making x the subject, we get;

x × 8/8 + y × 12/8 = 3840/8

x + 4/3·y = 480

x = 480 - 4/3·y

Substituting the value of x in equation (1) gives;

(480 - 4/3·y) × 35 + y × 20 = 9650

16800 - 80/3·y = 9650

y = 268.125

x = 480 - 4/3·y = 480 - 4/3×268.125 = 122.5

Therefore, she can make 122 Styrofoam lions and 268 Styrofoam Husky's

The maximum profit, she makes is therefore given by the following equation;

The maximum profit = 122 × 2.5 + 268 × 3 = $1109.

5 0

3 years ago

THE TOPIC IS: AREA OF CIRCLES!! PLEASE HELP ME WITH THIS QUESTION!!! WHATS THE ANSWER?? I WILL GIVE YOU BRAINLIEST AND A THANKS!

emmainna [20.7K]

9514 1404 393

Answer:

49π m² ≈ 154 m²

Step-by-step explanation:

The formula for the area of a circle is usually remembered as ...

A = πr² . . . . . for radius r

Here, we're given the diameter. We can either figure the radius from the diameter and use this formula, or we can rewrite the formula to use the diameter.

r = d/2 = (14 m)/2 = 7 m

A = π(7 m)² = 49π m² . . . . . "exact" answer

Sometimes when multiples of 7 are involved, we like to use π ≈ 22/7. Using that value, the area is ...

A = 49π m² = 49(22/7) m² = 154 m² . . . . . approximation using π = 22/7

Often, algebra problems insist on using the value π = 3.14. For that value, the area is ...

A = 49π m² = 49(3.14) m² = 153.86 m² . . . . . approximation using π = 3.14

Using the "pi button" on your calculator, the numeric answer is ...

A ≈ 49(3.14159265359) m² ≈ 153.938 m² . . . . using "pi button"

_____

If we rewrite the formula to use the diameter directly, then the area is ...

A = π(d/2)² = (π/4)d²

For the diameter of 14 m, this is ...

A = (π/4)(14 m²) = π(196/4) m² = 49π m² . . . . same as above

5 0

3 years ago

Is AABC-AXYZ? If so, identify the similarity postulate or theorem that

Nostrana [21]

Answer:

D would be the answer

Step-by-step explanation:

Mark as brainliest

8 0

4 years ago