What is the sum of the first five terms of the geometric sequence in which

In this 3x3 square, you can use only numbers from 1-9, to make all the rows and columns equal to 15. Good luck to the person sol

bulgar [2K]

Answer:

Hello,

Step-by-step explanation:

The well-known magic square. (first apparition in China).

Here it the methode du Marquis de Liouville: (odd square:3,5,7,9,11,13,...)

We are going to put successively the number from 1 to n² (here n=3)

We imagine that the square is put on a sphere;

We begin in the middle of the last line where we put 1

ICI:

We move in direction SE of one case and put le next number

until we reach of multiple of n

After have reached a multiple of n, we move verticaly of one case

and we go to ICI until we reach n²

8 0

3 years ago

Need help ASAP!!!!!!

Mnenie [13.5K]

Answer:

Mean = 2.95

Median = 3

Step-by-step explanation:

The mean of the number of visits of 40 adults to the gym is

$\dfrac{0\cdot 4+1\cdot 3+2\cdot 12+3\cdot 5+4\cdot 8+5\cdot 5+6\cdot 2+7\cdot 1}{40}=\\ \\=\dfrac{3+24+15+32+25+12+7}{40}=\dfrac{118}{40}=2.95$

The median of the data is the average number between 20th and 21th terms (because 40 is even number, so the middle term is the average between two middle terms).

20th term = 3 visits

21th term = 3 visits

Hence, median is 3 visits

6 0

3 years ago

Toya can run one lap of the track in 1 min. 3 sec., which is 90% of her younger sister niki's time. what is niki's time for one

Alex

Hello!

1 minute 3 seconds = 63 seconds

We must found out 63 is 90% of what number, using the percentage formula:

90 * 100 / 63 = 70

70 seconds = 1 minute 10 seconds

So, Niki's time for one lap is 1 minute 10 seconds (70 seconds).

5 0

3 years ago

Suppose the lifetime of a cell phone battery is normally distributed with a mean of 36 months and a standard deviation of 2 mont

solong [7]

Answer:

They should guarantee the lifetime of their batteries for 32 months.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Mean of 36 months and a standard deviation of 2 months.

This means that $\mu = 36, \sigma = 2$