This question is incomplete, the complete question is;
In a survey, 55% of the voters support a particular referendum. If 40 voters are chosen at random,
find the mean and variance for the number of voters who support the referendum.
Answer:
a) The Mean is 22
b) Variance is 9.9
Step-by-step explanation:
Given that;
55% of the voters support a particular referendum p = 0.55
q = 1 - p = 1 - 0.55 = 0.45
sample size n = 40
a)
Mean = sample size n × p
Mean = 40 × 0.55
Mean = 22
Therefore the Mean is 22
b)
Variance = n × p × q
so we substitute
Variance = 40 × 0.55 × 0.45
Variance = 9.9
Therefore the Variance is 9.9
$4 / 8 = 50 cents per pen
.5 * 5 = 2.50
.5 * 3 = 1.50
Ivan pays $2.50 and Jeff pays $1.50
Answer:
This is one of a variety of "subtraction solutions"--basically a different way to subtract by breaking numbers down into 10-digit chunks. It's not especially helpful for small subtraction problems, but as math gets more complicated, this method will come in handy.
Step-by-step explanation:
Here's an example: Jim had a bag of 15 jelly beans. He eats 8. How many jelly beans does he have left? <u>Take apart the number to make a 10. Then subtract.</u>
Here, you need to "take apart" the 8 to make your 15 jelly beans 10, then you subtract the remainder of 8 to get your solution. In other words,
--"take apart" 8 into 5 and 3 (because you're going to need a 5 to make 15 into 10). 15 minus 5 equals 10. HOORAY! You have your 10. Now, subtract the remaining 3. 10 minus 3 equals 7. Huzzah--your final answer!
On paper, the problem looks like this:
<u>15 - 8 (</u><u>5, 3</u><u>) = ?</u>
15 - 5 = 10
10 - 3 = 7
So...15 - 8 = 7
