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2 years ago

Kelly runs a distance of 100 metres in a time of 10.52 seconds.

Mathematics

1 answer:

ad-work [718]2 years ago

8 0

Answer:

Upper bound for distance = 100.49. This is the highest number that you can round up to get 10.52.

Lower bound for time = 10.515 seconds. This is the lowest number that you can round up to get 10.52.

Upper bound for average speed = Upper bound for distance divided by upper bound for time.

100.49/10.5249 = 9.548 seconds.

Lower bound for average speed = Lower bound for distance divided by lower bound for time.

99.5 / 10.515 = 9.463 seconds.

Step-by-step explanation:

Hope this helps you out.

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240 students to 12 teachers as ratio

grigory [225]

Answer:

1 : 20 20 students for every 1 teacher

Step-by-step explanation:

divide both sides by 12

7 0

1 year ago

Calculate the standard deviation. Variance = 107.76. Mean = 34.2

Llana [10]

Answer:

The standard deviation is 10.38

Step-by-step explanation:

Given;

Variance, v = 107.76

mean, x = 34.2

The standard deviation is given by;

standard deviation = √variance

standard deviation = √107.76

standard deviation = 10.381

standard deviation = 10.38 (two decimal places)

Therefore, the standard deviation is 10.38

8 0

1 year ago

Two hockey teams, the Winnipeg Jets (yay!) and the Toronto Maple Leafs (boo!), miraculously make it to

monitta

Answer:

There is a 54% chance that the Jets will win the Stanley Cup.

Step-by-step explanation:

Since two hockey teams, the Winnipeg Jets and the Toronto Maple Leafs, miraculously make it to the Stanley Cup finals, where as soon as a team wins 3 games, the championship is over, and the schedule for the playoffs for home games is: Jets - Leafs - Jets - Leafs - Jets; since if the Jets are playing at home, there is a 60% chance they'll win, while if they are playing on the road, there is a 45% chance they'll win, to find the probability that the Jets win the Stanley Cup the following calculation must be performed:

(0.60 + 0.45 + 0.60 + 0.45 + 0.60) / 5 = X

2.70 / 5 = X

0.54 = X

Thus, there is a 54% chance that the Jets will win the Stanley Cup.

7 0

1 year ago

PLEASE HELP: Choose the function whose graph is given by:

DIA [1.3K]

Answer:

The function of the graph is y = 3 cos (4x) ⇒ answer A

Step-by-step explanation:

- If the equation is y = A cos (B x)

* A is the amplitude

- The amplitude is the height from highest to lowest points and

divide the answer by 2

* The period is 2π/B

- The period is the distance from one peak to the next peak

* Lets look to the graph

- The maximum value is 3 and the minimum value is -3

∵ The height from the maximum point to the minimum point is

3 - (-3) = 3 + 3 = 6

∴ The amplitude is 6/2 = 3

∵ A is the amplitude

∴ A = 3

- The distance between two consecutive peaks is π/2

∵ The period is the distance from one peak to the next peak

∴ The period = π/2

∵ The period = 2π/B

∴ 2π/B = π/2 ⇒ divide both sides by π

∴ 2/B = 1/2 ⇒ by using cross multiplication

∴ B = 4

- Lets write the form of the function

∵ y = A cos (Bx)

∵ A = 3 and B = 4

∴ y = 3 cos (4x)

* The function of the graph is y = 3 cos (4x)

4 0

1 year ago

A standard weight known to weigh 10 grams. Some suspect bias in weights due to manufacturing process. To assess the accuracy of

notsponge [240]

Answer:

a) The 98% confidence interval for the mean weight is between 10.00409 grams and 10.00471 grams

b) 49 measurements are needed.

Step-by-step explanation:

Question a:

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

$\alpha = \frac{1 - 0.98}{2} = 0.01$

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

That is z with a pvalue of $1 - 0.01 = 0.99$ , so Z = 2.327.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 2.327\frac{0.0003}{\sqrt{5}} = 0.00031$

The lower end of the interval is the sample mean subtracted by M. So it is 10.0044 - 0.00031 = 10.00409 grams

The upper end of the interval is the sample mean added to M. So it is 10 + 0.00031 = 10.00471 grams

The 98% confidence interval for the mean weight is between 10.00409 grams and 10.00471 grams.

(b) How many measurements must be averaged to get a margin of error of +/- 0.0001 with 98% confidence?

We have to find n for which M = 0.0001. So

$M = z\frac{\sigma}{\sqrt{n}}$

$0.0001 = 2.327\frac{0.0003}{\sqrt{n}}$

$0.0001\sqrt{n} = 2.327*0.0003$

$\sqrt{n} = \frac{2.327*0.0003}{0.0001}$

$(\sqrt{n})^2 = (\frac{2.327*0.0003}{0.0001})^2$

$n = 48.73$

Rounding up

49 measurements are needed.

7 0

1 year ago