John sent 45 text messages in 9 minutes. What is the unit rate? Explain your answer.

Need help with math problem if do get 5 star

777dan777 [17]

Answer:

d) 63 square units

Step-by-step explanation:

x = 3 units (base - b)

y = 6 units (width - w)

h = 7 units (length and height - l and h)

Area of a rectangle: l*w
Area of a triangle: 1/2*b*h

For the triangles:

Area of a triangle: 1/2*b*h

A = 1/2 * 3 * 7

A = 1/2 * 21

A = 10.5

*Since there are two triangles, it would be 10.5 * 2 = 21

For the rectangle:

Area of a rectangle: l*w

A = 7 * 6

A = 42

Now, we add them together:

A = 42 + 21

A = 63 square units

Therefore, the area of the parallelogram is 63 square units

Hope this helps!

6 0

3 years ago

3 posters cost 24.50, so how many can you buy with 171.50

Ilia_Sergeevich [38]

Answer:

21

Step-by-step explanation:

24.50 / 3 = 49/6

5 0

3 years ago

Read 2 more answers

The measures of the angles of a triangle are shown in the figure below. Solve for x.

morpeh [17]

Answer:

63

Step-by-step explanation:

40+77=117

180-117=63

3 0

3 years ago

Read 2 more answers

A local fish market is selling fish and lobsters by the pound. The fish costs $5.25 a pound, while the lobster costs $10.50 a po

Arturiano [62]

The fish market sell 16 pound of fish and 12.5 pound of lobster.

5 0

3 years ago

Read 2 more answers

A self proclaimed psychic was tested for ESP. The psychic was presented with 200 cards face down and asked to determine if the c

swat32

Answer:

The 95% confidence interval would be given (0.172;0.288).

We are confident at 95% that the true probability that the psychic correctly identifies the symbol on the card in a random trial is between (0.172;0.288).

We can conclude that her random guessing would have got her correct 20% of the time. Since the confidence interval contains 0.2, she has no psychic powers, rather she just guessed it like normal people. Any person could have got it correct this many times.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Description in words of the parameter p

$p$ represent the probability that the psychic correctly identifies the symbol on the card in a random trial

$\hat p$ represent the estimated probability that the psychic correctly identifies the symbol on the card in a random trial

n=200 is the sample size required

$z_{\alpha/2}$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Numerical estimate for p

In order to estimate a proportion we use this formula:

$\hat p =\frac{X}{n}$ where X represent the cases successful

$\hat p=\frac{46}{200}=0.23$ represent the estimated probability that the psychic correctly identifies the symbol on the card in a random trial

Confidence interval

The confidence interval for a proportion is given by this formula:

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 95% confidence interval the value of $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.96$

And replacing into the confidence interval formula we got:

$0.23 - 1.96 \sqrt{\frac{0.23(1-0.23)}{200}}=0.172$

$0.23 + 1.96 \sqrt{\frac{0.23(1-0.23)}{200}}=0.288$

And the 95% confidence interval would be given (0.172;0.288).

We are confident at 95% that the true probability that the psychic correctly identifies the symbol on the card in a random trial is between (0.172;0.288).

We can conclude that her random guessing would have got her correct 20% of the time. Since the confidence interval contains 0.2, she has no psychic powers, rather she just guessed it like normal people. Any person could have got it correct this many times.

6 0

4 years ago