Answer:
35
Step-by-step explanation:
Here we see 5 black keys for every 7 white keys.
So the ratio is 5:7
If we need 49 white keys, find the amount we scale the original ratio by:
49/7 = 7
So we are scaling by a factor of 7.
The number of black keys would be 5 * the scale of 7. = 35
So there should be 35 black keys.
Answer:
At the 5% level, BAOI can infer that the average time to complete does not exceeds 60 hours.
Step-by-step explanation:
From the question we are told that
The population mean is 
The sample size is 
The sample mean is 
The standard deviation is 
The null hypothesis is 
The alternative 
Here we would assume the level of significance of this test to be

Next we will obtain the critical value of the level of significance from the normal distribution table, the value is 
Generally the test statistics is mathematically represented as

substituting values


Looking at the value of t and
we see that
hence we fail to reject the null hypothesis
This means that there no sufficient evidence to conclude that it takes more than 60 hours to complete the course
So
At the 5% level, BAOI can infer that the average time to complete does not exceeds 60 hours.
(x) is an element of a real number. This means it could be an integer, fraction or irrational number.
* As x approaches infinity, y approaches infinity.
* As x approaches minus infinity, y approaches 0.
-------------
Domain:
(x) is an element of a real number
Range:
y>0
Well when two angles are supplementary they equal 180.
So if angle A is 80 degrees then that would mean that angle B equals 100 degrees.
Hope This Helped :)