The office of student services at a large western state university maintains information on the study habits of its full-time st
udents. their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. the hours studied follows the normal distribution with a standard deviation of six hours. suppose we select a random sample of 144 current students. what is the probability that the mean of this sample is less than 19.25 hours? g
1 answer:
A suitable probability calculator can tell you the probability is about 6.7%.
_____
The standard deviation of the distribution of sample means is the population standard deviation (6) divided by the square root of the sample size (√144=12). Thus, your threshold is about (19.25-20)/(6/12) = -1.5 standard deviations from the mean.
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Answer:
Step-by-step explanation:
Divide the tens column dividend by the divisor.
Multiply the divisor by the quotient in the tens place column.
Subtract the product from the divisor.
Bring down the dividend in the ones column and repeat.
okay so look at the image down below
Answer:
Step-by-step explanation:
The equation for that is
If we subtract over the 70, we have a quadratic that we can factor to solve for the values of x that will make that equation true.
Now we need the factors of 70 that will either add or subtract to give us the linear term of 3. The factors of 70 that will work are 10 and 7. 10 times 7 is 70, and 10 - 7 = 3:
and now we will factor by grouping:
and factor out what's common:
The factor (x + 10) is common, so we will now factor that out:
By the Zero Product Property, either x + 10 = 0 or x - 7 = 0, so x = -10 or 7
Those are the 2 numbers that will work.
simplifies to
100 - 30 which does in fact equal 70. OR
which simplifies to
49 + 21 which also equals 70.
So you're done!