Answer:
b 2,3,8
Step-by-step explanation:
Y=234678
Z=278910
X=12358
234678910 n 12358
=238
Step-by-step explanation:
an object and its shadow create a right-angled triangle.
2 objects and their shadows create 2 similar right-angled triangles.
that means the angles are the same, and the side lengths of one triangle all correlate with the corresponding side lengths of the other triangle via the same factor.
so,
42 × f = 6
f = 6/42 = 1/7
the length of Joel's shadow is then
20 × f = 20 × 1/7 = 2.857142857... ft

I'm not sure why ± that sybol isn't working
all together you can write

Ughh just ignore the "A" symbol .-.
Answer:
Step-by-step explanation:
Given that a professor sets a standard examination at the end of each semester for all sections of a course. The variance of the scores on this test is typically very close to 300.

(Two tailed test for variance )
Sample variance =480
We can use chi square test for testing of hypothesis
Test statistic = 
p value = 0.0100
Since p <0.05 our significance level, we reject H0.
The sample variance cannot be claimed as equal to 300.