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: 4.1 feet : 4 feet
Step-by-step explanation:
From the question, we are informed that Bradley estimated the height of a tree at 2.5 meters. Carla estimated that tree's height at 8 feet.
The conversion ratio be used to compare Bradley's and Carla's estimates of the tree's height when measured in feet goes thus:
Since 1 feet = 0.305 meters
2.5 meters will be = 2.5/0.305 = 8.2 feet
Therefore the conversion ratio will be:.
= 8.2 : 8
Reducing to lowest term will be
= 4.1 feet : 4 feet.
= 4.1 : 4
Yes, you need to make the denominators the same. 2/3 becomes 8/12. So now you add 7/12 and 8/12, getting 15/12. But you're not done you need to simplify 15/12. The answer is 1 1/4.