Answer:
We need a sample size of least 119
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Sample size needed
At least n, in which n is found when 
We don't know the proportion, so we use
, which is when we would need the largest sample size.






Rounding up
We need a sample size of least 119
Answer: The area of the triangle is 252 :)
Step-by-step explanation:
M = 6
L = 6
K = 7
6 x 6 = 36 x 7 = 252
The area of the triangle is 252 :)
Answer:
The percentle for Abby's score was the 89.62nd percentile.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation(which is the square root of the variance)
, 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.
Abby's mom score:
93rd percentile in the math SAT exam. In 1982 the mean score was 503 and the variance of the scores was 9604.
93rd percentile. X when Z has a pvalue of 0.93. So X when Z = 1.476.

So




Abby's score
She scored 648.

So



has a pvalue of 0.8962.
The percentle for Abby's score was the 89.62nd percentile.
Answer: The length of the line B'C" is 1 unit.
Step-by-step explanation:
Given: Triangle ABC is dilated by a scale factor of 0.5 with the origin as the center of dilation , resulting in the image Triangle A'B'C'.
If A (2,2), B= (4,3) and C=(6,3).
Distance between (a,b) and (c,d): 
Then, BC 

Length of image = scale factor x length in original figure
B'C' = 0.5 × BC
= 0.5 × 2
= 1 unit
Hence, the length of the line B'C" is 1 unit.