Samples of size 60 are drawn from a large population known to have a mean of 78 and a standard deviation of 12. What proportion of these samples would we expect to have a mean greater than 80? a
0.566
b
0.098
c
Almost none
d
0.434
e
0.901

0.098

Step-by-step explanation: First you’ll need to find the sample distribution mean and standard deviation (which is 78 and 1.55). Then you plug it into calculator using normal approximation cause n is large: normalcdf(80,100,78,1.55)

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.

x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

step-by-step explanation:

last month maria hiked the 5-mile mountain trail a number of times and she hiked the 10-mile canal trail several times. let x represent the number of times she hiked the 5-mile trail, and let y represent the number of times she hiked the 10-mile trail. if she hiked a total of 90 miles, which equation can be used to find the number of times maria hiked each trail? x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x