Answer:
a) 0.71
b) 0.9863
Step-by-step explanation:
a. Given the mean prices of a house is $403,000 and the standard deviation is $278,000
-The probability the probability that the selected house is valued at less than $500,000 is obtained by summing the frequencies of prices below $500,000:

Hence, the probability of a house price below $500,000 is 0.71
b. -Let X be the mean price of a randomly selected house.
-Since the sample size 40 is greater than 30, we assume normal distribution.
-The probability can therefore be calculated as follows:

Thus, the probability that the mean value of the 40 houses is less than $500,000 is 0.9863
Answer:

Step-by-step explanation:
The sum of an infinite geometric series is expressed according to the formula;
where;
a is the first term of the series
r is the common ratio
If the sum of an infinite geometric series is three times the first term, this is expressed as 
Substitute
into the formula above to get the common ratio r;


open the parenthesis

subtract 3 from both sides

<em>Hence the common ratio of this series is </em>
<em></em>
Answer:
m∠S = 29.5
Explanation:
Q
S
R
In this triangle, QR = SQ, which means its an isosceles triangle, angle S and R is similar.
<u>Thus solve:</u>
m∠S = (180° - 121°)/2
m∠S = 29.5°
If a figure has exactly three sides, then it is not a triangle.
Answer:
A
Step-by-step explanation:
Round and estimate the sum.
3.41 + 8.051
3 + 8 = 11
3.65 + 7.992
4 + 8 = 12
4.25 + 8.103
4 + 8 = 12
4.89 + 7.431
5 + 7 = 12
The first option is correct.