We need to find the probability of the card chosen at random is yellow or brown.
So, since there are 3 yellow cards and 7 brown cards, the total numbers of cards that are yellow or brown is:
Now, the probability that the chosen card is yellow or brown can be found by dividing the above value by the total number of cards in the box.
The total number of cards in the box is:
Thus, that probability is given by:
Therefore, the answer is:
By applying z-score formula we got that if a reporter determines a mean order time of 63 minutes then value o Z is 1.19
<h3>What is standard deviation?</h3>Standard deviation is a number used to tell how measurements for a group are spread out from the average (mean), or expected value
Here given that
The owners of an eyeglass store claim that they fill customers' orders, on average, in 60 minutes with a standard deviation of 15. 9 minutes. Based on a random sample of 40 orders, a reporter determines a mean order time of 63 minutes
mean=μ=60
standard deviation=σ=15.9
number of sample=n=40
Now we can calculate z by z-score formula as
By applying z-score formula we got that if a reporter determines a mean order time of 63 minutes then value o Z is 1.19
To learn more about standard deviation visit :brainly.com/question/12402189