Answer:
1/2 or one half
Step-by-step explanation:
Initially to make the problem a bit more manageable ignore the .25 hours and just solve for 7 hours.
If he runs 5.5 miles per hour this would be considered his rate. So you can multiply 5.5 miles by the 7 hours he ran. This will give you the distance he ran after 7 hours. But in the problem he runs for an extra quarter of an hour so how do we include this in our answer.
First, figure out the rate of how far he runs every quarter of an hour. To compute this take your original rate 5.5 mi/hr and divide it by 4 to get it in terms of quarters of an hour: 5.5/4 = 1.375 <--- add this to your previous answer to get the total distance he ran.
We can calculate (62 + 90) / 2 = 76. it's <span>known that 95% lies between the mean and twice the standard deviation. </span><span>if the mean is "μ" and the standard deviation is "σ": </span><span>μ-2σ and μ+2σ. i</span><span>f μ=76, then </span><span>76+2σ = 90, so 2σ = 14, so σ = 7.
</span>
<span>the mean is 76 and the standard deviation 7. </span>
