Write an explicit formula for an, then th term of the sequence 75, 15, 3, ..

Nitella [24]

If you add them all together (7+4+7=18) the answer would be C.

8 0

3 years ago

A tractor, starting from a stationary position, drives down the road. It accelerates at 4 m/s2 for 10 seconds, then travels at a

chubhunter [2.5K]

Answer:

B. 1400 meters.

Step-by-step explanation:

According to the statement, there are two stages for the motion of the tractor, in which we need to find the travelled distance:

(i) Uniform accelerated motion.

$s_{i} = s_{o,i} +v_{o,i}\cdot t_{i} + \frac{1}{2}\cdot a\cdot t_{i}^{2}$ (1)

$v_{i} = v_{o,i}+a\cdot t_{i}$ (2)

Where:

$s_{o,i}$ - Initial position of the tractor, measured in meters.

$s_{i}$ - Final position of the tractor, measured in meters.

$v_{o,i}$ - Initial velocity of the tractor, measured in meters per second.

$t_{i}$ - Time, measured in seconds.

$a$ - Acceleration, measured in meters per square second.

$v_{i}$ - Final velocity of the tractor, measured in meters per second.

(ii) Uniform motion.

$s_{ii} = s_{i} + v_{i}\cdot t_{ii}$ (3)

Where:

$s_{ii}$ - Final position of the tractor, measured in meters.

$t_{ii}$ - Time, measured in seconds.

The distance covered by the tractor ( $\Delta s$ ), measured in meters, is:

$\Delta s = s_{ii}$ (4)

If we know that $a = 4\,\frac{m}{s^{2}}$ , $t_{i} = 10\,s$ , $v_{o,i} = 0\,\frac{m}{s}$ , $s_{o,i} = 0\,m$ and $t_{ii} = 30\,s$ , then distance covered by the tractor is:

By (1) and (2):

$s_{i} = 0\,m + \left(0\,\frac{m}{s} \right)\cdot (10\,s)+ \frac{1}{2}\cdot \left(4\,\frac{m}{s^{2}} \right) \cdot (10\,s)^{2}$

$s_{i} = 200\,m$

$v_{i} = \left(0\,\frac{m}{s} \right)+\left(4\,\frac{m}{s^{2}} \right)\cdot (10\,s)$

$v_{i} = 40\,\frac{m}{s}$

By (3):

$s_{ii} = 200\,m + \left(40\,\frac{m}{s} \right)\cdot (30\,s)$

$s_{ii} = 1400\,m$

By (4):

$\Delta s = 1400\,m$

The correct answer is B.

4 0

3 years ago

A woman is 5 1⁄7 inches taller than her daughter. The woman is 66 1⁄7 inches tall. How tall is her daughter?

Svet_ta [14]

To make the problem easier, I’m going to convert these to improper fractions.
A woman is 36/7 inches taller and she’s 463/7 inches tall. Her daughter is (463/7) - (36/7) inches tall. 463-36 is 427. She is 427/7 inches tall or 61 inches tall.

4 0

3 years ago

Assume that the results of your class' statistics test are normally distributed. You know that you scored 1 standard deviation a

Gnom [1K]

Answer:

84%

Step-by-step explanation:

We have to remember that z-scores are values to find probabilities for any normal distribution using the standard normal distribution, a conversion of the normal distribution to find probabilities related to that distribution. One way to find the above z-scores is:

$\\ z = \frac{x - \mu}{\sigma}$

As a result, we can say that one standard deviation above the mean is equal to a z-score = 1, or that one standard deviation below the mean is equal to a z-score = -1, to take some examples.

The corresponding cumulative probability for a z-score = 1 (one standard deviation above the mean) can be obtained from the cumulative standard normal table, that is, the cumulative probabilities from z= -4 (four standard deviations below the mean) to the value corresponding to this z-score = 1.

Thus, for a z-score = 1, the cumulative standard normal table gives us a value of P(x<z=1) = 0.84134 or 84.134. In other words, below z = 1, there are 84.134% of cases below this value.

Applying this for the case in the question, the percentage of test scores below 69 (one standard deviation above the mean) is, thus, 84.134%, and rounding to the nearest whole number is simply 84%.

6 0

3 years ago

I NEED HELP FAST!

irakobra [83]

Answer:

y = x - 5

Step-by-step explanation:

: )

7 0

3 years ago