Find the focus of the parabola y =

Jesse has reached 16% of his weekly reading time goal so far this week. If he has read for a total of

bekas [8.4K]

200 min
16/100=32/x
16x=3200
X=200

6 0

1 year ago

Read 2 more answers

The following data represent the length of life in

Natali [406]

Answer:

(a) For the stem-and-leaf plot, we need to organise all data in columns, one column is the stem and a second column is the leaf, but in this case, stems are going to be the digits to the left of the decimal point, and leafs are the digits to the right of the decimal point:

Stem Leaf

0 2 2 2 3 3 4 5 7

1 0 2 3 5 5 8

2 0 3 5

3 0 3

4 0 5 7

5 0 5 6 9

6 0 0 0 5

(b) Relative frequency distribution.

Remember that, a relative frequency is calculated dividing the absolute frequency by the total data, in this case, we approximated to the hundredth.

Length of life Absolute Frequency Relative Frequency % Relative Freq.

0.2 3 0.1 10

0.3 2 0.07 7

0.4 1 0.03 3

0.5 1 0.03 3

0.7 1 0.03 3

1.0 1 0.03 3

1.2 1 0.03 3

1.3 1 0.03 3

1.5 2 0.07 7

1.8 1 0.03 3

2.0 1 0.03 3

2.3 1 0.03 3

2.5 1 0.03 3

3.0 1 0.03 3

3.3 1 0.03 3

4.0 1 0.03 3

4.5 1 0.03 3

4.7 1 0.03 3

5.0 1 0.03 3

5.5 1 0.03 3

5.6 1 0.03 3

5.9 1 0.03 3

6.0 3 0.10 10

6.5 1 0.03 3

Total 30

(c)

To calculate the sample mean we need to sum all number, which results: 83.9. Then, we divide this result to the total 30, which result: 2.80.

The sample range is the difference between the highest and the lowest value: 6.5 - 0.2 = 6.3.

The sample standard deviation is calculated trough the following process:

Step 1: Subtract the mean from each number.

Step 2: Square each result.

Step 3: Add the squared deviations.

Step 4: Divide the sum by one less the total.

Step 5: Take the square root, and there you have it.

Doing this steps, the result is 2.22.

This last process is attached:

4 0

1 year ago

Please answer all of them need this

VikaD [51]

First Question

For a better understanding of the solution provided here please find the first attached file which has the diagram of the the isosceles trapezoid.

We dropped perpendiculars from C and D to intersect AB at Q and P respectively.

As can be seen in $\Delta BCQ$ , we can easily find the values of CQ and BQ.

Since, $Sin(75^0)=\frac{CQ}{8}$

$\therefore CQ=8\times Sin(75^0)\approx 7.73$ ft

In a similar manner we can find BQ as:

$Cos(75^0)=\frac{BQ}{8}$

$BQ\approx2.07$ ft

All these values can be found in the diagram attached.

Thus, because of the inherent symmetry of the isosceles trapezoid, PQ can be found as:

$PQ=22-(AP+QB)=22-(2.07+2.07)=17.86$

Let us now consider $\Delta AQC$

We can apply the Pythagorean Theorem here to find the length of the diagonal AC which is the hypotenuse of $\Delta AQC$ .

$AC=\sqrt{(AQ)^2+(QC)^2}=\sqrt{(AP+PQ)^2+(QC)^2}=\sqrt{(2.07+17.86)^2+(7.73)^2}\approx21.38$ feet.

Thus, out of the given options, Option B is the closest and hence is the answer.

Second Question

For this question we can directly apply the formula for the area of a triangle using sines which is as:

Area= $\frac{1}{2}$ (First Side)(Second Side)(Sine of the angle between the two sides)

Thus, from the given data,

Area= $\frac{1}{2}\times 218.5\times 224.5\times sin(58.2^0)\approx20845$ $m^2$

Therefore, Option D is the correct option.

Third Question

For this question we will apply the Sine Rule to the $\Delta ABC$ given to us.

Thus, from the triangle we will have:

$\frac{AB}{Sin(\angle C)}=\frac{BC}{Sin(\angle A)}$

$\frac{c}{Sin(\angle C)}=\frac{a}{Sin(\angle A)}$

$\frac{17}{Sin(25^0)}=\frac{a}{Sin(45^0)}$

This gives $a$ to be:

$a\approx28.44$

Which is not close to any of the given options.

Fourth Question

Please find the second attachment for a better understanding of the solution provided her.

As can be clearly seen from the attached diagram, we can apply the Cosine Rule here to find the return distance of the plane which is CA.

$AC=\sqrt{(AB)^2+(BC)^2-2(AB)(BC)\times Cos(\angle B)}$

$\therefore AC=\sqrt{(172.20)^2+(111.64)^2-2(172.20)(111.64)\times Cos(177.29^0)}\approx283.8$ miles.

Thus, Option D is the answer.

8 0

2 years ago

Read 2 more answers

Ashley recently opened a store that uses only natural ingredients. She wants to advertise her products by distributing bags of s

Elenna [48]

I will rewrite the question for better understanding:

Ashley recently opened a store that uses only natural ingredients. She wants to advertise her products by distributing bags of samples in her neighborhood. It takes Ashley 2/3 of a minute to prepare one bag. It takes each of her friends 75% longer to prepare a bag. How many hours will it take Ashley and 4 of her friends to prepare 1575 bags of samples?

Answer:

5.3 hours

Explanation:

1) Time it takes Ashley to preprate one bag:

2/3 min

2) Time it takes each friend of Ashley: 75% more than 2/3 min

75% × 2/3 min = 0.75 × 2/3 min = 3/4 × 2/3 min= 2/4 min = 1/2 min = 0.5 min

2/3 min + 1/2 min = 7/6 min

3) Time it takes Ashley and the 4 friends working along to prepare one bag:

Convert each time into a rate, since you can set that the total rate of Ashley along with her four friends is equal to the sum of each rate:

Rate of Ashley: 1 bag / (2/3) min = 3/2 bag/min

Rate of each friend: 1 bag / (7/6) min = 6/7 bag/min

Rate of Ashley and 4 friends = 3/2 bag/min + 4 × 6/7 bag/min = (3/2 +24/7) bag/min = 69/14 bag/min

4) Time of prepare 1575 bags of samples:

time = number of bags / number of bags per min = 1,575 bags / (69/14) bags/min = 319.56 min

5) Convert minutes to hours:

356.56 min × 1 hour / 60 min = 5.3 hours

3 0

1 year ago

A collection of 108 coins containing only quarters and nickels is worth $21. A table titled Coin Collection showing Number of Co

harina [27]

Answer:

q = 108-n

Step-by-step explanation:

Given: 108 coins containing only quarters and nickels

q = 108-n

since total number of coins is 108, and n= number of nickels

If you want to know how many of each kind of coin, read on:

First solve the number of quarters and nickels.

If all 108 coins are quarters, the value is 108*0.25 = $27

Since this value exceed the actual by 27-21 = $6,

we replace a number of quarters by nickels.

Each replacement will reduce the value by 25 - 5 = 20 cents = 0.2 dollars.

So it will take 6/0.2 = 30 replacements.

Therefore there are 108-35 = 78 quarters and 30 nickels.

8 0

1 year ago

Read 2 more answers

Find the focus of the parabola y = –1/4(x + 3)^2 + 2.