Given:
The International Space Station takes 644 minutes to orbit Earth 7 times.
To find:
The time taken by each orbit.
Solution:
Total time = 644 minutes
Total number of orbits =7
Now,



So, the required time is 92 minutes.
Therefore, you are correct and all options are incorrect.
Answer:

Step-by-step explanation:
Given:
The expression to simplify is given as:

In order to simplify this, we have to use the law of indices.
1. 
So, 
Substitute this value in the above expression. This gives,

Now, we use another law of indices.
2. 
So, 
Substitute these values in the above expression. This gives,

Finally, we further simplify it using the law 
So, 
Therefore, the given expression is simplified as:

Answer:
no, it's 81
Step-by-step explanation:
9×9=81 hope that this helps you and have a great day :)
Answer:
D. a = 60 and b = 58.8
Step-by-step explanation:
Z-score:
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

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.
Z-score for data point a is 0.
This means that a is the mean, that is, a = 60.
The z-score for data point b is -0.4.
This means that b must be a value below the mean, that is, a value below 60.
The option that satisfies a = 60 and b < 60 is option D, which is the answer.