K/3 + 4 -2k = -9k
First you add 9k to both sides
<span>k/3 + 4 -2k = -9k
</span> +9k +9k
<span>k/3 + 4 + 7k = 0
</span>
Now subtract 4 from both sides
k/3 + 4 + 7<span>k = 0
</span> -4 -4
k/3 + 7<span>k = -4
</span>
Now multiply 3 by both sides
k/3 + 7<span>k = -4
</span>x3 x3 x3
k +21k = -12
Now add k + 21k
22k = -12
Now divide both sides by 22
<span>22k = -12
</span>----- -----
22 22
k = -6/11
Answer:The mean number of checks written per day = 0.3370
The standard deviation = 0.5805
The variance = 0.3370
Step-by-step explanation:
Let the random variable x represent the number of checks he wrote in one day.
Given : The number of checks written in last year = 123
Let the number of days in the year must be 365.
Now, the mean number of checks written per day will be :-

We know that in Poisson distribution , the variance is equals to the mean value .


Thus, Standard deviation = 0.5805
You would need 105 of sodium I found how much increase there was from 30 to 75 by doing 75/30 which is 2.5 that means the new amount of sodium would be 2.5 times 42 which is 105. You could also set up ratios and cross multiply like the picture I sent