Answer:
The standard deviation of the speeds of cars travelling on California freeway is 6.0088 miles per hour.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by

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 This p-value is the probability that the value of the measure is greater than X.
In this problem, we have that:
Suppose that the speeds of cars travelling on California freeways are normally distributed with a mean of 61 miles/hour. This means that
.
The highway patrol's policy is to issue tickets for cars with speeds exceeding 75 miles/hour. The records show that exactly 1% of the speeds exceed this limit. This means that the pvalue of Z when
is 0.99. This is 
So





The standard deviation of the speeds of cars travelling on California freeway is 6.0088 miles per hour.
Answer: 3 < y < 9
Please mark me brainliest
Answer:
a) 21%
b) 45.5%
c) 26.4%
Step-by-step explanation:
Given the supplied information, a table of probabilities can be constructed. (See the attachment.) The numbers across the bottom reflect the given ratios of customers selecting the different gas types. The numbers in the cells are those bottom numbers multiplied by the percentage that fill the tank (or not). The numbers on the right are the sums of the numbers in each row.
a) The top center cell in the table answers this question. It it the product ...
p(plus)×p(fill | plus) = 0.35×0.60 = 0.21 = 21%
__
b) The sum on the right answers this question:
p(fill) = 45.5%
__
c) The ratio of the first column number (12%) to the row sum for Fill (45.5%) answers this question:
p(regular | fill) = 12%/45.5% ≈ 26.4%
Answer:

Step-by-step explanation:
Using the distributive property to expand, we have

Squaring each term, we have

The mistake was that
not
Using the fact that
the right answer would be
.
Answer:
The answers are
1) (√9)^2 = 9
2) 9 1/2 = 3
√9 = 3
9 1/2 = √9