Answer:
Step-by-step explanation:
The given trigonometric equation is 
.
We can either use the Pythagorean identity or the right angle triangle to solve for 
.
According to the Pythagorean identity,
Recall that, the cosine function is an even function, therefore
.
We substitute this value in to the above Pythagorean identity to get;
But we were given that,
, so we choose the negative value.
The correct answer is B
Answer:
t=-2
Step-by-step explanation:
(t+9)20=140
Distribute the 20
20t +180 = 140
Subtract 180 from each side
20t +180-180 = 140-180
20t = -40
Divide by 20
20t/20 = -40/20
t=-2
Answer:
The correct option is C. either a t test or an analysis of variance can be performed.
Step-by-step explanation:
Consider the provided information.
- The t-test, is used for whether the means of two groups are equal or not. The assumption for the test is that both groups are sampled from normal distributions with equal variances.
- Analysis of Variance (ANOVA) is a statistical method evaluating variations between two or more methods. ANOVA is used in a study to analyze the gaps between group methods.
- ANOVA is used not for specific differences between means, but for general testing.
- The chi-squared test is often used to evaluate whether there was a significant difference in one or more groups between the predicted frequencies and the observed frequencies.
Hence, Either a t test or an analysis of variance can be performed to determine whether the means of two population are equal.
Therefore, the correct option is C. either a t test or an analysis of variance can be performed.
1. B 2. A i’m pretty sure they are right
I think its supposed to be divide so i think C. would be the answer
