y = ( 3 * x ) - 2.
This is because the card costs for 3 $ and should be multiplied by the number of total cards she buys in that particular day. So 3 * x.
Now as she has got a 2$ off coupon, whatever the total is she gets 2 dollars off on that price. So we will subtract 2 at that time. FInally all this summed up would be equal to y.
Step-by-step explanation:
Im trying to get pts
Answer:
And we can find this probability with the following difference and using the normal standard table or excel we have:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability with the following difference and using the normal standard table or excel we have:
Ya I think it is also the second one