Step-by-step explanation:
sin(s+t) = sin(s)+cos(t) which results
(sin(s)×cos(t))/(cos(s)cos(t)) + (cos(s)×sin(t))/(cos(s)cos(t))
knowing that tan=sin/cos and that cos/cos=1 and sin/sin=1
resulting tan s ×1 + tan t × 1 = tan s + tan t
It will equal (4,6) for x and y
Answer:
n = 98, that is, she scored at the 98th percentile.
Step-by-step explanation:
When the distribution is normal, we use the z-score formula.
In a set with mean 
and standard deviation 
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
She scored 38, so 
Test scores are normally distributed with a mean of 25 and a standard deviation of 6.4.
This means that 
Find the percentile:
We have to find the pvalue of Z. So
has a pvalue of 0.98(rounding to two decimal places).
So n = 98, that is, she scored at the 98th percentile.
The approximate probability that she checked a social website first, then a school-related website is 0.267.
First step is to calculate the Total number of websites
Total number of websites=Number of school websites+Number of social websites
Total number of websites=2+4
Total number of websites=6
Second step
Probability of checking the social website first
Probability of checking social website=Number of social websites/Total number of websites
Probability of checking social website= 4/6
Third step
Since one social website is checked which means that she is left with 3 social website and 2 school websites
Total number websites=2+3
Total number websites=5
Forth step
Probability of checking social website=Number of school websites/Total number websites
Probability of checking social website=2/5
Fifth step
Probability= 4/6 x 2/5 = 0.2666
Probability=0.267(Approximately)
Inconclusion the approximate probability that she checked a social website first, then a school-related website is 0.267.
Learn more about probability here:brainly.com/question/25688842
