Answer:
20
Step-by-step explanation:
Answer:
68% of jazz CDs play between 45 and 59 minutes.
Step-by-step explanation:
<u>The correct question is:</u> The playing time X of jazz CDs has the normal distribution with mean 52 and standard deviation 7; N(52, 7).
According to the 68-95-99.7 rule, what percentage of jazz CDs play between 45 and 59 minutes?
Let X = <u>playing time of jazz CDs</u>
SO, X ~ Normal()
The z-score probability distribution for the normal distribution is given by;
Z = ~ N(0,1)
Now, according to the 68-95-99.7 rule, it is stated that;
- 68% of the data values lie within one standard deviation points from the mean.
- 95% of the data values lie within two standard deviation points from the mean.
- 99.7% of the data values lie within three standard deviation points from the mean.
Here, we have to find the percentage of jazz CDs play between 45 and 59 minutes;
For 45 minutes, z-score is = = -1
For 59 minutes, z-score is = = 1
This means that our data values lie within 1 standard deviation points, so it is stated that 68% of jazz CDs play between 45 and 59 minutes.
Here we will tell you what 7 percent of 522 (7% of 522) is and then show you how we calculated it. The answer to "What is 7 percent of 522?" is:
36.54
Answer:
The pieces are 55 inches, 55 inches and 46 inches long
Step-by-step explanation:
A 13ft board is to be cut into three pieces consisting of two equal length ones. The third one is 9in shorter than each of the other two.
Let us first convert the length of the board to inches:
1 ft = 12 inches
13 ft = 12 * 13 = 156 inches
Let the length of each of the other two pieces be x.
Therefore, the length of the third piece is (x - 9)
Therefore, the sum of the lengths of the three pieces is equal to 156 inches. This means that:
x + x + (x - 9) = 156
x + x + x - 9 = 156
=> 3x = 156 + 9
3x = 165
x = 165 / 3 = 55 inches
Each of the first two pieces are 55 inches long.
The length of the third piece will be:
55 - 9 = 46 inches
The pieces are 55 inches, 55 inches and 46 inches long.
I'm pretty sure it's the square. The square can be divided into 4 equal parts, each part able to reflect each other.